Minutes of American Institute of i in in^ ' and Metallurgical Engineers Conference on Open-Hearth Steel Manufacture

HELD AT NETHERLAND PLAZA HOTEL, CINCINNATI, APRIL 11 AND 12, 1935

THURSDAY MORNING SESSION

April 11, 1935

At the first session of the Eighteenth Confereilce of the Open-Hearth Committee of the American Institute of Mining and Metallurgical Engineers, a t the Netherland Plaza Hotel, Cincinnati, the Chairman, Leo F. Reinartz, presiding, called the meeting to drder a t 10 o'clock.

Registration a t the meeting was as follows:-

Ahl, Charles E. Courtney Fire Brick Co., Monongahela, Pa. Albaugh, W. P. American Rolling Mill Co., Ashland, Ky. Andrews, Joseph B. Andrews Steel Co., Newport, Icy. Annan, R. Green Union Mining Co., Pittsburgh

Bankson, John P. Barnes, H. C. Bates, A. Allan Beckert, F. F. Belleville, R. R. Bensley, M. D. Blackford, George L. Bliss, W. Carter Bohn, Edward L. Bower, R. S. Bradley, H. S. Bradley, M. J . Bray, J . L. Breunich, John T. Brizzolara, R. D. Brown, Ely E. Bruce, L. F. Buchanan, Zdward D. Buck, W. E. Buell, William C. Jr. Bulmer, William C.

Harhison-Walker Refractories Co., Cleveland American Rolling Mill Co., Middletown, Ohio Case School of Applied Science, Cleveland Gulf States Steel Co., Gadsden, Ala. Joseph Dixon Crucible Co., Jersey City Shenango-Penn Mold Co., Sharpsville, Pa. Andrews Steel Co., Newport, Ky. Scullin Steel Co., St. Louis North American Refractories Co., Cleveland Corrigan-McKinney Steel Co., Cleveland Shenango-Penn Mold Co., Pittsburgh Leeds & Northrup Co., Philadelphia Purdue University, West Lafayette, Ind. Amer. Inst. of Mining Engineers, New York American Steel Foundries, Chicago Wheeling Steel Corpn., Portsmouth, Ohio Joseph Dixon Crucible Co., Jersey City American Rolling Mill Co., Butler, Pa. Granite City Steel Co., Granite City, Ill. P.O.Box 6093, Cleveland Blaw-Knox Co., Pittsburgh

Cain, George D. Republic Steel Corpn., Warren, Ohio Campbell, J. L. Ohio Steel Foundry Co., Lima, Ohio Cavender, John H. North American Refractories Co., Cleveland Charman, Walter M. Ferro Engineering Co., Cleveland

3

Childs, Blair Chipman, John Christopher, C. F. Clifford, Ralph K. Cone, Edrvin F. Corriston, J . W. Cossctt, George W. Coxey, J. S. Crabtree, Marion Crane, Clyde C. Crawford, J . C. Cromer, C. E. Crow, Thomas J . B.

Danforth, George L. Jr. Darlington, H. J. '

Day, C. M. de Laval, Carl G. Dimmick, R. B. Dimmitt, C. E. Dockum, John F. Dor6, Floyd F. Dougherty, Sylvester J. Dowling, Eugene Dowling, J. W. Downcr, Huntington Dunn, Harold S.

Eaton, Gordon F. Edmiston, R. J . Eclls, Samuel Eichmeyer, B. E. Ekholm, L. E. Epstein, Samuel Erdman, W. W.

Faithful, William R. Farrell, F. C. Fitzgerald, A. E. Fitzsimmons, Joseph P. Fleming, M. Fleming, ~ i l l i a m R. Fondersmith, Charlcs R. Foss, Feodore F. Foster, Carl

Gnlvi11, John 1C. Garms, L. J . Gathmann, Elnil Gathmann, Emil, Jr. Gathmann, Mark H. Gelder, Ralph H. Gifford, A. W.

Union Mining Co., Pittsburgh American Rolling Mill Co., Middlctown, Ohio American Locomotive Co., Latrobe, Pa. Continental Stcel Corpn., Kokomo, Ind. Reinhold Publishing Corpn., New York E. J. Lavino & Co., Philadelphia American Rolling Mill Co., Ashland, Icy. Industrial Silica Corpn., Youngstown, Ohio American Steel Foundries, Granitc City, Ill. Keystone Steel & Wire Co., Peoria, Ill. Johns-Manville Corpn., New York Granite City Steel Co., Granite City, Ill. Shefficld Steel Corpn., Kansas City, Mo.

Open-Hearth Combustion Co., Chicago Youngstown Sheet & Tube Co., Youngstorv~~, Ohio Hick~nan Williams & Co., St. Louis Electro-Metallurgical Sales Corpn., Pittsburgh American Rolling Mill Co., Butler, Pa. Wehn Insulation, Inc., Cincinnati Pittsburgh Plate Glass Co., Barberton, Ohio American Steel Foundries, Alliance, Ohio Weirton Steel Co., Weirton, W. Va. Johns-Manville Corpn., Cleveland General Refractories Co., Pittsburgh Basic Dolomite, Inc., Clcveland Harbison-Walker Refractories Co., Portslnouth, Ohio

Ferro-Engineering Co., Cleveland United States Graphite Co., Pittsburgh Basic Dolomite, Inc., Cleveland Basic Dolomite, Inc., St. Louis Harrisburg Steel Corpn., Harrisburg, Pa. Battelle Memorial Institute, Columbus, Ohio J . E. Baker Co., York, Pa.

Central Iron & Steel Co., Harrisburg, Pa. Republic Steel Corpn.,' Warren, Ohio General Refractories Co., Philadelphia Andrews Steel Co., Newport, Ky. Hickman Williams & Co., Cincinnati Andrews Steel Co., Newport, Ky. American Rolling Mill Co., Middletown, Ohio Wheeling Steel Corpn., Wheeling, W. Va. American Steel Foundries, East St. Louis, Ill.

Ohio Stccl Fouildries Co., Lima., Ohio Ferro-Engineering Co., CLeveland Gathmann Engineering Co., Baltimore Gathmann Engineering Co., Baltimore G:~thm:tnn Engineering Co., Pittsburgh American Rolling Mill Co., Ashland, Ky. Canadian Refractories, Ltd., Montreal, Canada

Godard, Frank B. United States Graphite Co., Pittsburgh Good, R. C. Electro-Metallurgical Co., Pittsburgh Goodpasture, J . M. Henry Disston & Sons, Inc., Philadelphia Graf, A. J. Andrews Steel Co., Newport, Ky. Green, John R. Brown Instrument Co., Philadelphia Gr~f i th , R. E. E. J . Lavino & Co., Pittsburgh Grim, H. G. Heppenstall Co., Pittsburgh

Hague, C. E. Hamilton, A. K. Harder, E. W. Harrison, Kent Harvey, J . W. Heist, C. H. Henry, C. R. Hill, E. G. Hoch, A. J . Hohn, Fmnk X. Hopkins, J . C. Hubbard, H. B. Humphreys, E. B.

H. A. Brassert & Co.,,Cleveland M. H. Treadwell Co., Chicago Falk Corporation, Milwaukee, Wis. Colorado Fuel & Iron Co., Pueblo, Colo. Vulcan Mold & Iron Co., Latrobe, Pa. Youngstown, Ohio Alan Wood Steel Co., Conshohocken, Pa. Lukens Steel Co., Coatesville, Pa. Wheeling Steel Corpn., Portsmouth, Ohio Scullin Steel Co., St. Louis General Refractories Co., Cleveland Inland Steel Co., East Chicago, ~ n d i a n i American Steel Foundries, Alliance, Ohio

Jdcobs, J . E. Heppenstall Co., Pittsburgh Jenkins, S. M. Armstrong Cork Products Co., New York Jones, Otis I,. Illinois Clay Products Co., Joliet, Ill.

Kauffman, E. J. Kennedy, Walter, King, Frank A. Kinnear, H. B. Kitto, William C. Knox, John D. . Kral, C. A. Krogh, A. E. Kurtz, Thomas N.

Largcy, H. D. Lcathers, E. H. 'Lee, Harlcy C. Lewis, David Lippert, Thornas W. Loftus, Fred H. Longenecker, Charles Loring, A. D. Lovcll. E. R.

Luckie, J. B. Luetscher, Oliver P.'

. . . MacIsaac, P. A. Marz, T . W. Maxon, S. E. McBurney, J . E.

Valley Mold & Iron Corpn., Hubbard, Ohio National Fireproofing Corpn., Pittsburgh Weirton Steel Co., Weirton, W. Va. Battelle Memorial Institute, Columbus, Ohio Pittsburgh Steel Co., Monessen, Pa. Associate Editor-Steel, Cleveland Wheeling Steel Corpn., Steubenville, Ohio Brown Instrument Co., Philadelphia North American Refractories Co., Pittsburgh

Basic Dolomite, Inc., Cleveland Wheeling Steel Corpn., Stcubenville, Ohio Basic Dolomite, Inc., Columbus, Ohio Colorado Fuel & Iron Co., Pueblo, Colo. The Iron Age, New York Union Mining Co., Pittsburgh Steel Publications, Inc., Pittsburgh '

Eagle-Picher Lead Co., Cincinnati Calumet & Hecla Consolidated Coppcr Co., Hubbcll,

Mich. I<. J . Lavino & Co., Pittsburgh Consulting Engineer, Tiskilwa, Ill.

Dominion Steel & Coal Corpn., Sydney, Nova Scotia Andrews Steel Co., Newport, Ky. New Jersey Zinc Co., New York Owens-Illinois Glass Co., Alton, Ill. . ' ,

ti 1935 OPEN-HEARTH CONFERENCE MINUTES

McClclland, Howard Shenango-Penn Mold Co., Youngstown, Ohio McConnell, IA. I?. VesuviusCrucible Co., Birmingham, Ala. McConnell, W. C. Republic Steel Corpn., Massillon, Ohio McCutcheon, Kenneth C. American Rolling Mill Co., Ashland, Ky. McDonald, J. H. Algoma Steel Co., Sault Ste Marie, Ont. McDonnell, E. J. Blaw-Knos Co., Pittsburgh McGeary, W. A. Kittanning Brick Co., Kittanning, Pa. McGuigan, R. J. . Wheeling Steel Corpn., Steubenville, Ohio McKimn~, Paul J. Otis Steel Co., Cleveland McKune, Frank B. Steel Company of Canada, Hamilton, ~ a n a d a McVey, Ernmet Wheeling Steel Corpn., Steubenville, Ohio Mead, H. G. Leeds & Northrup Co., Philadelphia Meihack, Albert W. Empire Sheet & Tin Plate Co., Mansfield, Ohio Menke, William J. Shenango-Penn Mold Co., Sharpsville, Pa. Mercur, R. A,, Jr. John A. Roebling's Sons Co., Trenton, N.J. Merkt, G. A. Morgan Construction Co., Worcester, Mass. Merten, Willia~n J. Pittsburgh Rolls Corpn., Pittsburgh Miller, J. A. Vanadium Corpn. of America, Pittsburgh Miller, Lewis B. Johns-Manville Corpn., Manville, N.J. Miller, W. A. Continental Steel Corpn., Kokomo, Ind. Mills, Jaines W. Granite City Steel Co., Granite City, Ill. Morgan, M. E. Gulf States Steel Co., Alabama City, Ala. Moore, C. D. Worth Steel Co., Claymont, Del. Muir, Samuel B. Ncw Castle Hot Top Co., New Castle, Pa. Murphy, D. J. Scullin. Steel Co., St. Louis ,

Naisniith, Harry Open-Hearth Combustion Co., Chicago Newbrander, S. M. Weirton Steel Co., Weirton, W. Va. Nichols, A. S. Illinois Clay Products Co., Joliet, Ill. Norris, Frank G. American Rolling Mill Co., Middletown, Ohio

Ogden, Daniel J,. American Metal Co., Carteret, N.J. - Ogden, W. B. Valley Mold & Iron Corpn., Hubbard, Ohio Oliver, Edward G. Gathmann Engineering Co., Baltimore Ome, Charles S. Jr. Ross-Tacony Crucible Co., Chicago

Peterson, G. A. Perro-Engineering Co., Clevcland Phillips, D. Gordon Globe Brick Co., East Liverpool, Ohio Pigott, ~oward%. \N E. J. Lavino & Co., Chicago Protheroe, Alfred W. Vesuvius Crucible Co., Swissvale, Pa.

Ramscy, E. 1,. Raugh, Jarnes P: Rautio, L. J. Reagan, W. J. Rcilly, W. J . Reinartz, Leo F. Reyndcrs, Charlton Richardson, S. A. Robertson, A. Robertson, H. G. Robertson, H. S. Rosc, William F.

Wisconsin Steel Co., Chicago -

Gcneral Refractories Co., Cleveland American Rolling Mill Co., Ashland, Ky. Edgewater Stcel Co., Oakmont, Pa. Youngstown Sheet & Tube Co., Youngstown, Ohio American Rolling Mill Co., Middletown, Ohio International Chromium Process Corpn., New York Empire Sheet & Tin Plate Co., Mansfield, Ohio American Steel Foundries, Alliance, Ohio Americz~n Steel Foundries, Granite City, Ill. Harbison-Walker Refractories Co., Pittsburgh Pratt & Letchworth Co., Buffalo

Sainuels, M. L. Sanford, S. A. Schaup, W.'T. Schroeder, Fred W.

- Schueler, J. L. Scott, Thomas T. Seil, ~ i l b b r t E. Selmi, L. Shaeffer, Paul H. Shallcross, W. M. Shannon, M. C. Sjostrorn, Ivar Sloan, Charles H. Jr. Smith, Earl A. Srnith, M. A. Smith, R. C. Snyder, L. C. Soler, Gilbert Spence, J. L. Starr, George W. Stewart, J. M. Stone, R. H. Stremmel, Philip J. Stroup, Floyd

Thorpe, Drew Thurston, A. M. Tietig, Rudolph, Jr. Tisdale, N. F. Tranter, G. D. Troupe, J. W. Turner, W. A.

Vallette, J . J. Vignes, Jamcs C.

Wach, Loron W. Wallace, W. W. Walters, George D. Walters, J. D. Ward, Phillip R. Washburn, F. M. Washburn, M. J . Watkins, Don N. Watson, W. A. Wellings, W. G. Wheeler, Bradley F. White, Charles White, Walter H. Wickersharr, F. A. Williams, B. P. Williams, Clyde E.

Battelle Memorial Institute, Columbus, Ohio Stccl Engineering & Equipment Co., Pittsburgh Canadian Refractories Co., Pittsburgh A. P. Green Fire Brick Co., Mexico, Mo. Continental Steel Corpn., Kokorro, Ind. Sheffield Steel Corpn., Kansas City, Mo. E. J . Lavino & Co., Philadelphia Great Lakes Stcel Corpn., Dctroit Ohio Ferro-Alloys Corpn., Canton, Ohio Shallcross Controls, Inc., Milwaukee Gulf States Stcel Co., Gadsden, Ala. Hoganas Billeshoms-A.B., Hogganas, Swcden Andrews Steel Co., Newport, Ky. Andrews Steel Co., Newport, Ky. Edgcwatcr Stcel Co., Oakmont, Pa. Illinois Clay Products Co., Warren, Ohio Hickman Williams & Co., Cincinnati Timken Steel 8: Tube Co., Canton, Ohio Canadian Refractories, Ltd., Montreal, Qucbec Ohio Ferro-Alloys Corpn., Canton, Ohio Hickrnan Williarns & Co., Pittsburgh Vesuvius Crucible Co., Swissvale, Pa. Granite City Steel Co., Granite City, Ill. Tlrnken Steel & Tube Co., Canton, Ohio

Gencral Refractories Co., Philadclphia East Ohio Gas Co., Cleveland Andrews Steel Co., Cincinnati Molybdenum Corpn. of Anierica, Pittsburgh American Rolling Mill Co., Middletown, Ohio McFeely Brick Co., Pittsburgh McLain Eire Brick Co., Pittsburgh

United States Graphite Co., Saginaw, Mich. Ohio Ferro-Alloys Corpn., Canton, Ohio

Atlantic Steel Co., Atlanta Treadwell Construction Co., Pittsburgh Atlantic Steel Co., Atlanta Lukens Steel Co., Coatesville, Pa. Ferro Engineering Co., Cleveland Wisconsin Stecl Co., South Chicago, Ill. Eagle-Picher Sales Co., Cincinnati Blast Furnace & Stcel Plant, Pittsburgh Stowe Fuller Refractorics Co., Cleveland Titanium Alloy Mfg. Co., Nlagara Falls, N.Y. Bethlehem Steel Corpn., Buffalo General Steel Castings Co., Granite City, 111. Pittsburgh Rolls Corpn., Pittsburgh Carnegie Steel Go., Pittsburgh Valley Dolomite Co., St. Louis Battelle Memorial Institute, Columbus, Ohio

Williams, David P. Vulcan Mold & Iron Co., Latrobe, Pa. Williams, Edward R. Vulcan Mold & Iron Co., Latrobe, Pa.

Yeager, F. B. Blast Furnace & Steel Plant, Pittsburgh

Zerbe, William F. Central Iron & Steel Co., Harrisburg, Pa.

Introductory Address by the Chairman

CHAIRMAN REINARTZ.-We are meeting today in Cincinnati, for our eighteenth conference. I think you will all agree with me that we have probably more beautiful surroundings for this meeting than we have ever had before. And it appears probable that .we shall have the largest attendance of operating men we have ever had.

During the ten-year period from our first meeting our organization has grown from a small beginning into a Committee that has had a real influence on the development of the open-hearth industry.

Steel plant operations continue to test the stamina of open-hearth superintendents and men. The steel industry, in years gone by, has been termed "Prince and Pauper." From an operating if not from a financial standpoint, this is more true than ever today. We have had violent swings from very low to peak operations and back to sub-normal production within a period of a few months. Furnaces have had to be lighted after long shut-downs and, after a few weeks' or months' oper- ations, shut down again. Here is where insulation and sealing of thc complete furnace against infiltration of air will pay big dividends in reduced fuel to heat up the furnace, in lower fuel operating cost, and in less shut-down fuel if furnaces are not operated over the week end. We hope to develop the status of improvements in this field very com- pletely tomorrow.

I am sorry that our program does not permit time to discuss a t length some of the National legislation being proposed a t Washington for regulation of industry. Every steel plant man should interest himself personally in his Country's welfare to the extent that he studies the bills being presented and registers his protest against legislation which will be harmful to his own and his company's interest.

The 30-Hour bill, as now proposed, will not help our employees, and will hinder the efforts of our managements to pull us out of the "red." More leisure, no more pay, will be the worker's lot under i t ; and 25 per cent increase in labor rates, confusion and inefficiency will be the employ- er's reward, if this bill becomes a law. The increase in cost cannot be absorbed by the steel industry. I t must be passed on to the consumer.

This will decrease demand, and ultimately our working population will be in worse condition than now. History teaches us that real progress can- not be made except by greater daily production per worker. We must sell this idea to our workers.

Again, the Wagner Labor Disputes bill, ostensibly designed to avoid or prevent strife, will inevitably plunge our country into a series of labor disturbances and strikes such as we have not seen for many years. I t s enactment would set the stage for a conflict which would injure the relations between employees and employers for all time, and unquestion- ably would retard national recovery.

I t would further project the Government into the field of private employment relations. I t would strangle employees' representation plans which have been in satisfactory operation for many years, and are mutually desired by employees and employers.

The obvious intention of the bill is, through majority rule, to impose the closed shop upon industry and to create a monopoly in favor of professional labor unions.

This proposed law gives support to an organization, the American Federation of Labor, which has not been able, even with the sympathetic attitude of certain Government officials, to corral more than 10 per cent of the working population into its fold; and also to the Amalgamated Association of Iron and Steel Workers in the steel industry, whose officials in recent months have demonstrated that they cannot control their own small forces. I t will prevent a free exchange of ideas between management and men, and create suspicion and animosity where there should be understanding and harmony.

I t (very properly) would forbid coercion or intimidation on the part of employers; but i t offers nothing that would prevent outside labor organizations, their agents or members, from exercising any manner of violent coercion or intimidation against our employees.

This act is so vague in its terminology that the difficulties arising out of the interpretations would result in widespread confusion and uncer- tainty. It is legislation which cannot be enforced, even if passed as a law. The steel industry within the last few years has voluntarily done many things for the welfare of its employees. These benefits will be jeopardized by the passage of this bill.

At the same time, the Social Security bill, a hodge-podge of many ideas, would, by unprecedented enactment of taxation, principally on industry, try to cure, over-night, age-old problems of maladjustment of employment and old age, as well as other social problems.

As if that burden were not enough, this week Congress has written a

blank check for almost 5 billion dollars and given i t to our President to spend as he thinks best. Irrespective of politics, this is too much power to place in the hands of any man, especially since i t has been clearly demonstrated that the Administration has no clear-cut idea as to how to spend this huge sum of money. If the history of past centuries is any criterion, enormous expenditure of funds for public works has never primed the business pump; but i t has led to political abuse, graft and bureaucracy. We can only hope that our President will make use of the best talents available in this country to spend this huge sum of money wisely.

We should do our duty as American citizens, interested in industry's future, and make constructive suggestions to our representatives in Washington.

At present the steel industry has passed the peak of the Spring bulge in tonnage. Those plants serving the automotive industry have fared better than plants producing structural or railroad steel. Economists believe there will be a slow decline until June, and a quiet Summer, with an increase in operations in the Autumn. This rate of operation may be considerably modified by Government expenditures.

We have one consolation:-Each time one of these drastic changes in operating rates takes place, it makes us more flexible in adjusting our- selves to the next abnormal condition, which seems bound to arise.

Our Open-Hearth Committee can continue to be helpful by acting as a clearing house for discussion of problems which are of current interest and concern to our members. Such questions have been presented in our present program. I t is natural that some of these questions are asked quite regularly. Open-hearth practice is not static. In some plants we will find changes and progress have bcen made which, if given to the group, will be helpful to all of us.

Pit operations and mold practice are very important; they come in for considerable attention a t this session. Iron oxide control and European metallurgical developments continue to create subjects for discussion. Insulation and fuel economy are of paramount importance and will undoubtedly create considerable discussion.

VISITS TO Two STEEL MILLS

We have been invited to visit the Newport Rolling Mill Co. plant tonight. We have prepared cards to be signed during the day, signifying . who will make this trip. We are assured that we will be back in Cincin- nati by about 8:45 P. M.

Tomorrow, we will visit the ARMCO plant a t Middletown, Ohio.

We would like to have you signify your intention to go to Middletown on the cards provided. We need this information for two reasons:-

1. Trailsportation facilities. 2. Since this is our tenth anniversary, we have planned a dinner a t

Middletown (at Hotel Manchester) after our plant inspection. The return trip to Cincinnati will start from Middletown a t 7:00 P. M.

Mr. Shoffstahl, Manager of the International Nickel Co., has invited members of our Committee to visit the Huntington, West Virginia, plant on Saturday.

This year, we have reorganized our Open-Hearth Control Committee so as to give all parties interested in our activities representation. This is the Committee :- ~ M A N A ~ E M E N T SUPERINTENDENTS METALLURGISTS TECHNICAL R. K. Clifford E. L. Ramsey W. E. Buck C. E. Williams L. F. Reinartz C. Fondersmith . Dr. C. H. Herty, Jr.

J. D. Walters Carl Foster Frank. A. King H. B. Hubbard

PUBL~CITY COMMERCIAL A.I.M.E. J. D. Knox R. C. Good J. T. Breunich

You will notice that we have chosen men in such a way that all sections of our Country in which the majority of our constituency live will be represented. We expect to work closely with this Committee to make our programs as helpful as possible.

We are anxious to receive suggestions from our members for guidance in making plans for future meetings.

For the information of our visitors, a t these conferences we . have informal discussion of questions presented by our members for consideration.

To have a record of these discussions, we have them taken down by a stenographer, printed, and sent to member cornpanics, and to all those who register for our conferences. If anyone desires to speak "off the record," all heneed dois to call this to our attention, and our stenographer, as well as representatives of technical papers, will honor the request.

A new policy will be inaugurated a t this time. Our sales friends will be given an opportunity to advertise in our booklet, containing thc minutes of our meetings. The type of cover, and the general make-up of the minutes, will be improved. Mr. J. T . Breunich will be ready a t this meeting to accept your reservations for advertising space.

I repeat what I have said each year: "We get as much out of thesc conferences as wc put into them." If you have an unique or new scheme for reducing cost, or improving operations or quality, let the group know about it. Your frankness and cooperation will encourage others to do likewise.

(A pplnuse)

CHAIRMAN REINARTZ.-Our first topic is the general subject of Pit Practice. We have divided it into two parts:-Pit Piactice and Mold Practice. I have asked Mr. Tranter to lead off on Pit Practice. Mr. Tranter discussed some of these things a t the New York meeting of the Mining and Metallurgical Engineers. There were very few open-hearth men there; and as he has written a practical discussion 011 pit practice, I thought it would be worth while to have him repeat that paper a t this meeting.

Mr. Tranter!

Ladle and Teeming Practice in Steel Mills . '

MR. TRANTER.-In presenting this paper on Ladle and Teeming Practice, diversity of opinion may exist with respect to certain details,

. ' since each plant develops its particular methods to suit the needs of local conditions. To undertake a description of the numerous special features and individual practice followed by the various steel plants would require considerably more time than is allotted.

I t is not within the scope of this paper to attempt to set forth a practice which is a cure-all for the many problems connected with pit operations, nor to infer that other methods are less effective.

However, the practice described is being used very successfully in the manufacture of low-carbon rimming steels for sheet purposes. I t was developed through many years of experience in dealing with high tempera- tures and severe slag conditions.

The paper deals with the mechanical phase of the subject and empha- sizes those features of standard practice which are often neglected in the routine of pit operation.

The importance of ladle and teeming practice and its relationship to the yield and quality of the product has focused considerable attention on this phase of open-hearth operation.

Inherently bad steel cannot be made good steel by manipulation dur- ing teeming; but, through proper handling of "off heats," serious losses, which in many cases arise, can be greatly minimized. Conversely, good steel can be ruined as a result of poor workmanship in the pit and rendered unsuitable for application to orders where exacting surface and physical requirements are essential.

Many basic defects which develop in the semi-finished product, or carry through to the inspection table, have their origin in ladle and teem- ing practice; sufficient evidence having been secured to warrant careful

investigation of pit operations when an abnormal amount of such defccts occur.

I t should be understood that this paper is written from the standpoint of the problems involved in making satisfactory ingots for sheet rolling. Furthermore, since rimming steel is almost universally used for sheet manufacture, the data herein presented refer particularly to that type of steel.

Going back some 30 years in open-hearth history, the word pit properly described the hole into which the ladle was lowered to ieceive the metal tapped from the furnace. The working space was necessarily' limited and the disposal of slag, and metal overflowing the ladle, or lost because of breakouts, presented a serious problem. Furthermore, the equipment was rather crude in the light of present development.

In many cases no ladle stands were provided, the ladle being hung on , . the crane beneath the runner. When -delayed taps occurred, the ladle ' . was often held in position for Inany hours, thus tying up pit operations, with consequent delays to adjacent furnaces.

Because of crowded conditions, slagthimbles were not used and a network of cast steel triangles and old tapping bars, placed prior to tap- ping the heat, were the means for removing slag from the hole.

Furnaces of different capacities were frequently encountered and ladles- of different sizes had to be used, thus necessitating an auxiliary bail and hook to accommodate the various types.

The modern open-hearth plant with the elevated charging floor obviates the former unsatisfactory conditions, .since the pit is on ground level, with provision for more adequate working space to carry on the operations.

Ladle stands beneath the furnace runner relieve the necessity for holding the crane unnecessarily, a n d slag thimbles provide an effective means for slag disposal. Ladle cranes and runways have been designed . . for increased capacity and to provide a greater factor of safety.

Simultaneous with the improvement in engineering and plant layout has been the development of more suitable refractories, improved ladle equipment, and advancement in technique of the personnel. Engineering and type of equipment are important factors, however, despite certain limitations' in this respect, a n d a high degree of efficiency c a n be main- tained by attention to a number of important details.

In general, the factors affecting the origin of defects in ladle and teeming practice may be summarized as follows:-

1. Rulining stoppers resulting from mechanical 'failure of the stopper rod, stopper head, nozzle or manipulating mechanism.

2. Failure to clean ladles and molds properly between pourings, poor

lining practice,'failure of the refractories, and too rapid pouring' speeds. 3. Improper technique and manipulation in teeming thc mctal from

the ladle into the molds. 4. Mold design, temperature of molds a t time of teeming, cleaning and

conditioning molds, type of mold coatings and methods of applying them. 5. Capping ingots, elapsed time for pulling, stripping and charging

ingots into the soaking pits. Mechanical failure of the stopper rod and operating mechanism are

the more common causes for running stoppers. These difficulties can usually be traced to faulty stoppcr heads, sleeve brick, assembly of the rod or insufficient drying of the rod before use. A survey of a number of steel plants shows considerable variation with respect to the frequency of running stoppers. Some plants have very little difficulty, while in others it constitutes a major problem. Type of steel, size of heats, condi- tipn under which the metal is teemed, number of shut offs and skill of the personnel account for the varying degree of difficulties encountered.

Diversity of opinion exists on certain details of ladle practice. How-

, ever, each plant develops its particular methods to suit the needs of local conditions and to handle the type of product being made. In general, all are agreed on certain fundamentals, briefly described below.

Ladle brick should be sufficiently dense to prevent excessive slag penetration, and should have the proper constituents to resist the fusing action of the slag and metal. Physical properties are of equal importance with chemical analysis, and kiln conditions are an influencing factor.

Tight joints in the lining are obviously essential, taking into account the necessary allowance for expansion. By using the proper proportion of brick shapes-arch, wedge and squares-more uniform lining practice is obtained.

Stopper rod assembly requires workmanship of a rather specialized nature. Best results are obtained where the work is assigned to a regular stopper rod maker, who is responsible for assembling and drying rods used by all shifts.

The stopper head, usually made of graphite, is affixed to the lower end of the stopper rod by means of a bolt and key; in some plants, a screw- type head is used. In fitting the key-type head to the rod, i t should turn freely but not loosely. If too tight, expansion may cause the head to split during pouring; on the other hand, loose heads may burn off due to molten steel penetrating the joint. A tapered bottom sleeve into which the shank of the stopper head is fitted provides added protection a t this point.

It is important that the key slot in the rod be accurate, otherwise a poor fit will result. The bolt hole in the stopper head is plugged with a moist stopper head compound, usually obtained from the stopper head manufacturer. Past experience has shown too much variation in home- made compounds for uniform results.

Fire clay used to pack the joints between the sleeve brick should bc of flint-base clay of good quality. Experiments with various kinds of clay have shown that some grades arc entirely unsuited for this purpose. A special supply of clay should be maintained for stopper rod use, if that used for other purposcs is not of propir tcxturc. Ccrtain types of refrac- tory cements, now availablc, have provcd vcry satisfactory.

A drying oven is necessary for thoroughly drying the assembled rod before placing in the ladle. The vertical type is very satisfactory: This is designed for placing the new rods in one end and removing the dry rods from the other. An electric mono-rail hoist is used for lifting the assembled rod from the bench to a vertical position, where it is attached to a trolley operating on a system of channel supports to convey it through the furnace.

The furnace is equipped with a recording pyrometer and a definite drying cycle is followed. By assembling a daily supply of rods and holding a sufficient number of rods in the furnace a t all times, the drying cycle is automatically controlled.

The oven is constructed with four compartments, which is of special advantage where rods of different sizes are required. Carc must be taken in handling the rod after removal from the oven; i t should always be held in a vertical position, to avoid cracking in the joints.

The mechanism operating the vertical movement of the stopper rod in the ladle is usually lifted to raise the rod, and lowered to shut off the stream. This method has proved satisfactory from both an operating and a safety standpoint. Various controversies have arisen as to the relative merits of this method compared to that whereby the levcr is lowered to open the nozzle.

Nozzle setting requires careful attention to proper mixture of fire clay and loam used to ram the nozzle in place, size and contour of the cup to guide the stopper head properly into the nozzle opening, drying the surrounding clay and loam, setting the nozzle in a vertical position in 1 relation to the mold, and examination or testing for imperfections before use.

Grinding the nozzle cup has given satisfactory results, where a slight imperfection prevented a proper fit with the stopper head. Care must be

taken to avoid grinding the surface too deeply, otherwise the soft interior, beyond the point where the surface firing has toughened the brick, will be exposed.

Nozzle size to control properly the rate of pouring has been the subject for considerable discussion among steel makers. Nozzle size varies.with different types of steel and tons per heat. There are certain limitations in area beyond which the increased rate of pouring gives rise to interior defects in the ingot. The larger nozzle is more favorable to good ingot surface, but has a detrimental effect on the interior structure from the standpoint of blowholes, pipe and inclusions.

Where a large number of ingots are poured, necessitating frequent shut-offs, the double-nozzle system has overcome much of the difficulty arising from holding the metal too long in the ladle. While the use of the double nozzle does not exactly reduce the pouring time to one-half that required with the single nozzle, nevertheless, the decrease in the time required to teem is considerable. In pouring a heat of 28 18 X 39-inch iilgots with a single 2-inch nozzle, 24.53 minutes was required; whereas i t required 19.22 minutes when using two nozzles.

Oval-shaped nozzles have come into more general use and have special advantages where slab-shaped ingots are poured. The tendency for the metal stream to strike the mold wall on the narrow dimension has been greatly lessened.

Length of nozzle is also a factor; the tendency has been toward longer nozzles. A number of plants arc using nozzles 12 inches or more in length. An improverncnt is noted with the longer nozzle, in that it prevents spraying of the metal stream, to a considerable extent.

Nozzles, sleeves and stopper heads should be stored in a warm, dry place and allowed to season to some extent before use. The space betwecn adjacent furnace regenerators serves very well for this purpose. This procedure is particularly advantageous in cold weather, to avoid spalling or cracking when the assembled rod is placed in the drying oven.

LADLE DESIGN I

Ladle design has been given considerable thought and attention with increasing capacity of open-hearth furnaces. In many cases existing furnaces have been rebuilt for tapping larger heats, and certain limita- tions with respect to size, weight and design of ladles had to be overcome.

The effect of ferro-static pressure must be taken into account-largely a function of thc size and design of the ladle. A deep ladle increases the pressure, but a smaller area of the metal surface is exposed to the slag during the teeming opcration. On the other hand, a shallow ladle causes less "head" to the metal, but a greater surface of the metal comes in contact with the slag. Both extremes should be avoided by arriving a t a propcr ratio of height to diameter.

Oval ladles have been a solution where increased depth would be detrimental to quality, or where clearance and limitations of certain existing equipment would be a problem.

Welded ladles have made it possible to increase the size of heats where building columns, crane. runways and ladle cranes were of insuffil cient capacity to carry larger heats. The welded ladle is approximately 25 per cent lighter than other types of the same capacity.

The practice of insulating- ladles has been successfully accomplished, resulting in lower radiation loss through the shell. The insulation consists of approximately 1 to 1>5 inches of insulating cement applied with a trowel to the inside of the'tank. This practice had for its original ,

objective the use of a thinner lining, thereby increasing the capacity' of the ladle. The calculated radiation loss of the thinner lining' without insulation indicated too much heat transfer; therefore, the use of an insulating material was given a trial. After considerable experimentation a satisfactory insulating cement was found which served the purpose very well. While no actual heat-conductivity 'calculations have been made, . the outside of the ladle indicates to the touch only a slight increase in temperature. The thinner lining has been entirely satisfactory, and no decrease in service is noted.

Various types of fuel have been used for drying and heating ladles. Coke baskets, small slag pots, wood fires, natural gas and fuel oil are among the various methods employed. Effective application of heat for drying ladles, nozzles .and rods is a very important feature of good ladle practice.

Mold practice has co~lsiderable bearing on the life and service of the mold, together with the surface qualities of the ingot. The use of larger ingots has increased mold problems to no small extent, particularly the slab type, where the large flat area is very susceptible to fire cracks and gouges.

Design is important and the mold manufacturer is directing consider- able attention to this phase of the subject. Wall thickness, inside taper and radius of the corners are features being studied. Chemical analyses, physical condition of the iron and mold casting practice are impor- tant factors.

Relation of mold weight to ingot weight is taking on more importance, but considerable variation is noted when comparisons are made among different plants. The structure of ingots poured into sand molds has been found to consist almost entirely of columnar crystals; therefore, the

ratc of hcat transfer of the thin-wall versus the heavy-wall mold should be given consideration from this standpoint.

Greater importance is being attached to mold cleaning practice and its effect on steel quality and mold life. Inclusions, surface defects and mold stickers result from poorly cleaned molds. In many cases a haphazard job results where the mold-yard men are required to stand on top of the mold to perform the operation; the amount of cleaning in this case being more or less in inverse proportion to the temperature of the drag. This conditioil is further complicated. by a serious safety hazard.

A more effective job of cleaning is done where molds are placed on thc ground. Where certain limitations of equipment would necessitate too much time for this method, provision can be made for overhead cleaning, whereby a satisfactory job can be made. A movable platform operating over the train of molds provides a safe and effective basis for cleaning. Fewer men are required, because of less fatigue due to heat, and safety hazards are practically eliminated.

Slag, oxides and other foreign material are carefully scraped from the mold surface, after which the mold is hoisted and the stool scraped, and blown off with compressed air.

Various mold coatings are used, with graphite or tar predominating. Graphite is applied with a spray, and the mold surface brushed after application, to prevent dripping down the side. Molds are coated with tar, either by spraying the inside surface or dipping the entire mold into a tar bath.

A pouring cycle of approximately 8 to 10-hour intervals is usually established, to avoid pouring into molds which are either too hot or too cold. A temperature best described as "hand warm" will give most satisfactory results.

Mold failure, assuming that the mold is properly designed and cast, results from a number of causes. Grade and temperature of steel poured, time it is allowed to remain in the molds before stripping, and mechanical abuse are among the principal factors affecting mold life.

Deeply gouged stools are detrimental to mold life and definite rules should be established as to the depth of gouge permitted before the stool is taken out of service. Furthermore, the metal adhering to the butt of the ingot, patterned by the gouge in the stool, is a total loss to blooming mill yield. Obviously the proper economic balance must be maintained between yield, mold and stool life.

A mild steel plate of 14 to 16 gage placed on the stool prior to teeming decreases the wear caused by the stream when the nozzle is first opened. The fit between the bottom of the mold and the stool is also important,

otherwise excessive erosion of the bottom of the mold occurs and large fins are formed on the ingot.

Copper stools have been used to some extent for the purpose of increas- ing the life of both mold and stool. Experiments indicate that less goug- ing of the lower part of the mold occurs when it is used in conjunction with a copper stool. The longer life of the stool overcomes the tendency for stools to cut away, thus making a better fit with the bottom of the mold. Experiments along this line are being observed with considerable interest.

Where ilzgots, due to certain limitations of stripping equipment, must remain in the molds for a long period, fire cracking of the mold surface and gouges often result. Under such conditions consideration should be given to providing the necessary equipment so that molds may be removed promptly from the ingot.

The use of an extra drag of stripper buggies may bc used as an expe- dient in some cases. Mold life is materially decrcased where ingots are not stripped promptly.

Ingot defects arising from defective mold surface such as fire cracks and gouges cause varying degrees of surface trouble in rolling. In most cases, light gouges and fire cracks are removed by competent soak- ing pit heating.

If fire cracked too decply, the pattern cast on the ingot tends to lap- over during rolling, causing slivers and scabs. A defect resembling rolled-in scale may result from the same condition. Badly gouged molds are also the source of scabby bars, particularly wherc the gouge is heavy a t the bottom. This is especially true where ingots are rolled butt first.

Scabs resulting from stopper troubles are in most cases readily identi- fied. They vary from the size of a small coin to large patches covering a considerable portion of the bar. No reasonable amount of "washing" of such ingots in the soaking pits will clean up the surface.

The effect of running stoppers on the bar surface is variable. A full running stopper has been found, in many cases, to cause less surface trouble than a partial or leaky stopper. Very scabby bars result from the latter, due to freezing of patches or scabs on the ingot surface, which do not weld tightly to the surrounding metal.

A full running stopper, however, causes interior defects which in many cases are of such nature as to render the steel unfit from the stand- point of laminations and inclusions.

"Cold heats," also, are causes for scabby bars and certain-forms of

interior defects. In most cases they are primarily due to open-hcarth furnace conditions and are not the responsibility of the ladle crew.

Scabs often result from improper pouring technique. Where the stream is allowed to strike the mold wall, poured too slowly, or splashed because of opening the nozzle too suddenly, similar surface condi- tions result.

Good tecming practice is to open the nozzle slowly until a pool of metal several inches deep has formed in the bottom of the mold. This pool of metal serves as a cushion, thus preventing a certain amount of splash when the nozzle is opened to a full stream. When the ingot is teemed to approximately two-thirds to three-fourths the desired length, the stream should again be reduced and poured rather slowly until the mold is filled. This serves to "top off" the ingot with less splash and allows escape of a certain amount of the gas evolved.

The degrce of splash, beyond that normally controlled through the use of the proper size nozzle or by the steel pourer through manipulation, - becomes obviously an engineering problem, since it is a function of the size of heat, ladle dimension and height of mold.

Splash scabs of varying degrees are formed on the ingot surface due to conditions during pouring, and in most cases are scaled off in soaking pit heating. Where ingots tend to have subcutaneous blowholes closeJo the surface, heavy scaling is decidedly detrimental from the standpoint of seams and other defects origi~lating with "thin-skinned" ingots.

Experiments with the use of various mechanical methods for prevent- ing splash scabs have been made with rather indifferent results. Inserts made of various materials placed in the lower part of the mold, pouring through hollow. pipes, and the use of tun dishes have failed to make sufficient improvement in the final product to compensate for the added expense. Safety hazards, and in some cases even worse surface conditions, were the net result .of these experiments.

- "Thin-skinned " ingots also &use certain types of surface defects. In most cases such ingots are primarily due to pouring temperatures and deoxidation practice and are not the responsibility of the ladle crew. They are a very dangerous form of defect and give rise to seams, scabs and rolled-in scale on the bar surface.

I11 the manufacture of rimming steels, over-deoxidation must be carefully avoided. To prevent riser heats, which-in many cases are the result of over-deoxidation, i t is usual practice to under-deoxidize slightly in the ladle, and complete the treatment in the molds.

Observations on the pouring platform often ditqlose considerable variation in the practice of adding aluminum to ingots. Both- the

method of adding and the quantity used have considerable bearing on the quality of the product.

Large additions of aluminum to the ingot are riot advocated. Best results are,obtained where the ladle addition is sufficient to deoxidize the metal to the point where only a limited amount is required in the molds.

Prior to placing the cap on the ingot, it has been found beneficial to remove the slag or skum formed during the effervescing action in the molds. This material call be blown off with compressed air or removed by scraping with a wooden pole or paddle. This practice serves to prevent ingots from "blowing up" or spouting, a quality and safety hazard which otherwise frequently occurs where large slab ingots are poured.

Considerably more slag and'skum is formed on the top of ingots - worked in this manner, indicating possibly that more gas and inclusions

are expelled before solidification. Pulling heats too quickly after teeming has been found to have con-

siderable bearing on the formation of interior defects. Repeated experi- ments have demonstrated that certain types of laminations result from moving the ingot too quickly after pouring, and charging into the soaking pit too rapidly. The delay in holding the heat 15 or 20 minutes longer is more than compensated for by improved steel quality.

Reference has been made to the importance of technique on the part of the personnel. Maximum results are obtained where the organization receives constant and intensive training in standard methods and practice.

Technical literature, in the main, has dealt with the personal equation in a more or less abstract manner. The human element is a very impor- tant factor affecting ultimate results. With even the best of equip- ment, efficiency is largely dependent upon the knowledge and technique of the personnel.

To be effective, the training program must be practical and deal with specific items of practice and subsequent results. Group conferences, individual instruction by the foreman, together with frequent review and explanation of standard practice methods will materially assist in develop- ing a highly trained personnel.

The training program should incorporate the safety features of the work, as well as technique and operating practice. No operation in the steel plant presents more potential safety hazards than the open-hearth pit. Safe and efficient handling of molten metal and slag requires not only safe practice,on the part of the individual but also continual and special attention to the equipment.

Ladle trunnions should be inspected frequently for defects and flaws which may develop as a result of overflowing slag. Crane runways should be regularly checked for loose rivets and worn rails.

Regular inspection of ladle cranes covering mechanical, electrical and safety features is important. The illspection is more rigid where the inspection committee consists of persons who do not have direct super- vision of these particular cranes. Hoist cables should be arbitrarily renewed on a basis of total tonnage handled over a period of time. This varies from 300,000 to 400,000 gross tons, depending on the size of cables . and general conditions to which they are subjected.

Handling of oxygen equipment on the pouring platform presents safety hazards which can be overcome only by careful regulation of pressures, keeping oxygen hose in good condition, and proper use of the blow-pipe or lance. Wherever possible a central oxygen station piped to thc various poiilts of use will reduce waste and safety hazards to the minimum. Welded joints in the piping system are recommended.

Protective apparel such as leggings, jackets and goggles should be provided, with very definite and rigid rules established for their use. It is a paying proposition, from the standpoint of personal safety and more effective handling of bad heats, to provide the men with the necessary protection to cope with such emergencies.

Order and clean-up in the pit is an important factor and is funda- mental to good workmanship as m;ell as safety requirements. Quality of work reflects the general working conditions surrounding the job. Where skulls and pit scrap are cleaned up and shipped out daily, attention is more quickly focused on excessive scrap losses a t the time of occurrence. .

The emphasis which has been placed on ladle and teeming practice in the foregoing should not be construed to infer that all the ills of the steel business can be saddled on this particular phase of plant operation. Soaking pit heating and subsequent rollinghave an important bearing on the degree to which inherent defects are developed.

Through proper cooperation and working arrangement between the Open-Hearth and Blooming Mill Departments, the effect of certain types of defects originating in the ingot can be greatly minimized. Where the mill receives prompt notification of certain characteristics with respect to the behavior of the metal during teeming, added precautions may be taken and special treatment given in heating and rolling. The practical application of this plan whereby the two departments are brought into more close relationship has resulted in a large degree of success.

CHAIRMAN REINARTZ.-The meeting is now open for discussion on any of the points raised by Mr. Tranter's paper.

MR. MERCUR.-I would like to ask the best method for inspecting the trunnions on the ladle.

MR. T R A N T E R . - L ~ ~ ~ ~ trunnions are washed off with kerosene, which generally discloses any flaws or cracks which otherwise could not be seen. Incipient cracks are also noted which cannot be found by casual observation.

CHAIRMAN REINARTZ.-I might say that several years ago we had several very badly cracked ladle trunnion castings, which came from slag running over the top of the ladle onto the trunnions. We found that to be very dangerous, and our open-hearth men have taken steps since that time to eliminate that hazard. We had had some very dangerous cracks develop in our trunnions; but since that time no cracks have developed.

MR. SHANNON.-I should like to know how long the steel is held in the open-hearth pit.

MR. FONDERSMITH.--We believe the steel should be held in the pit an hour and 15 minutes from tapping time.

CHAIRMAN REINARTZ.--H~ is talking about rimming steel. Can anyone give the time killed high-carbon steel is held in the open- hearth pit?

MR. REAGAN.-I think the time of holding steel in the molds depends largely on the size of ingot. One cannot state any cut and dried time for all sizes of ingots; but we hold ingots weighing 3.25 net tons from 1% to 2 hours. Ingots weighing 4.35 net tons we hold from 2% to 3 hours, and ingots of 5.7 net tons, 3 to 335 hours from the time we finish pouring the heat. This is all high-carbon fully-killed steel.

CHAIRMAN REINARTZ.-M~. ICing, what is your experience? You have large size ingots, have you not?

MR. I<ING.-We have some large ingots. Our time on killed steel is about an hour and 15 minutes to an hour and a half. On rimming steel i t is about 1% hours, on account of taking the caps off, from the time we start pouring.

CHAIRMAN REINARTZ.-I understand from Mr. Reagan it is an hour and 15 minutes after he finishes pouring. That is on killed, high- carbon steel.

MR. KING.-It is an hour and 15 minutes on killed steel, and an hour and a half, on rimming steel.

CHAIRMAN REINARTZ.-Mr. Ramsey, what is your experience? MR. RAMSEY.-AS Mr. Reagan says, it depends entirely upon thc

size of the ingots and also upon the quality of the steel. We hold the 21-inch ingots an hour and 15 minutes to two hours in the molds and the 26-inch ingots from 2 to 3 hours, from the time we are through pouring.

CHAIRMAN REINARTZ.-DO YOU have the same practice on rim- ming steel?

MR. R A M S E Y . - ~ ~ do not make much rimming steel. I would say we ordinarily pull theheat about a half hour af ter ' f ini~hin~ teeming.

CHAIRMAN REINARTZ.--Does anyone ,else want to give us his experience?

MR. MERTEN.-If I understood. him correctly, Mr. Tranter states that he removes the surface defects of an ingot due to a. mold condition by heating in the soaking pit. I would like to know something about the mechanism of removal of these defects as well as the kind of defects which can be treated in this manner..'

MR. TRANTER.-some scabs are removed. by the usual scaling in soaking pit heating. If too heavy, however, they will .not be scaled off.

CHAIRMAN REINARTZ.-H~ means put a jacket of scale on the ingot in . - the soaking pit.

MR. T R A N T E R . - T ~ ~ ~ is a fire-cracked pattern on the ingot surface resulting from the mold surface.

CHAIRMAN REINARTZ.--H~ is talking about very low-carbon steels, under 0.10 per cent carbon. I think it makes a difference whether we ark discussing 0.10 pkr cent carbon or high-carbon or alloy steel. . MR. TRANTER.-YOU do not want to rely on your soaking pit too much there. (Laughter)

CHAIRMAN REINARTZ.-Mr. Smith, - Earl Smith. w h i t is your practice?

MR. EARL SMITH.-We let- our rimming steel ingots stand about 30 minutes after we finish pouring. The first section is pulled out as soon as we can get the caps off after it is rimmed.. It is put into the pit as soon as we can get it in. on the high-carbon steel it,depends on the size of the ingots. If it is poured into inverted mold killed steel, we leave i t in the molds 246 to 3 hours. These ingots weigh from 2 to 245 tons.

MR. DOUCHERTY.-I would like to ask Mr. Tranter a question with regard to the thickness of caps on rimming' steel and their effect on lamination. Have you noticed any? We sometimes find laminations in our finishing mills, but have not been able to tie them in with any variation in our practice, even.when the slabs are crbpbcd to clean and apparently solid steel.

MR. TRANTER.-I do not know whether I can answer that or not. Our caps are about 155 inches thick, I judge.

MR. FONDERSMITH. -T~~~ are about 134 inches and weigh 175 to 200 pounds, for use on 18. by 39-inch ingot molds.

MR. BOWER.-How soon do you start Lapping the rimmed ingots? MR. FONDERSMITH.-We start capping the heat on an 18 by 39-inch

ingot after i t is rimmed in ar6und 2 or 3 inches. Our caps are of such sizes that we cannot start sooner than that. The time varies on different heats, because of the different action you get in the molds and different temperature of the'metal. Some heats are capped sooner than others; i t is entirely according to the way the rim forms.

CHAIRMAN REINARTZ.-We will go to the next subject: "Has anyone tried basic linings for ladles? Runners?" A great many people believe that we would gain a lot in cleanliness of

steel by having basic linings. I am told Mr. McDonald has tried basic lining in a ladle. Mr. McDonald!

MR. MCDONALD.--We have tried basic linings; put in a lining with Magnefrit and cement. The cement was put in for a binder. We made eight heats on the lining. What developed was the slag would stick 'and skull formed on the bottom of the ladle. In removing i t the lining was damaged and had to be renewed. . The result of. our experience was on basic-lined ladle, a slag test taken before tapping contained 16.50 per cent SiO2 and 9.10 per cent phosphorus. A slag test taken from the ladle-after heat was poured contained 21.50 per cent SiOz and the phosphorus remained the same. On a brick-lined ladle a slag test before tapping was 9.30 per cent phos- phorus. The slag test from the ladle after heat was poured was 30.50 per cent SiOz and 6.70 per cent phosphorus.

The analyses from the ladles were: slol CAO At NO

Basic-lined.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.18 44.28 8 .65 Brick-lined. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.68 31.03 9.44

We did not try basic brick as a lining. We put in the basic lining about 255 inches fhick. We have found, as I believe everyone else has, that the phosphorus goes up and the manganese goes down, in last ingots of heat. We tried to prevent the return of the phosphorus to the steel and the loss of manganese, by putting in the basic lining. I think it could be worked out.

CHAIRMAN REINARTZ.-Has anjrone tried a basic lining in a ladle? MR. KITTO.-I have tried a small patch of magnesite brick-3 feet by

3 feet. It did not turn out satisfactorily. It kept growing up and had a blister on it. We did not notice any more skulling in the ladle. We just tried the experiment.

C H A I R ~ A N REINARTZ.-YOU mean the slag melted the brick? MR. K r ~ ~ o . - T h e slag seems to grow on i t in a kind of blister. It

does not cut away like the rest of the ladle brick.

TAPHOLE MAKJNG

CHAIRMAN R E I N A R T Z . - " M ~ ~ ~ O ~ to makc up tapholes-size-lifc- quality improvement if size maintained."

Mr. Albaugh! -

MR. ALBAUGH.:~~ have tried to keep our tapholes around 7 to 9 inches in diametcr. When we pipe our holes we usually use a mixture

called 695, in preference to the ordinary chrome. We have been getting very good results from it. We average 12 to 15 heats on a taphole, a t present. Our taphole is made up with raw dolomite throughout, except that on the inside we face.it over with synthetic dolomite, such as Magnefer, and we use a loam plug on the back side.

We have not tried any special brick for making up a taphole. CHAIRMAN REINARTZ.-MI.. J. D. Walters, do you have something to

say on this subject? MR. J. D. WALTERS.-We are still putting down tapholes with Mag-

nefer and 10 per cent cement. We have had very good results. CHAIRMAN REINARTZ.-Has anyone tried any special method of put-

ting in a tap hole? MR. HUMPHREYS.-We had to pipe our tapholes about every week.

I tried Basic Print Plastic, No. 695, and I find we do not have to pipe much more than once a-month. I t is a prepared affair from Canada.

CHAIRMAN REINARTZ.-M~. Mac~saac, have you tried any special way to make up tapholes?

MR. MACISAAC.-In connection with tapholes, where we are making a variety of grades of steel, it is our practice to have a very close range of carbon and i t is very important to watch tapholes. I think everyone connected with an open-hearth knows the importance of keeping the taphole right.

For years we have been trying out different materials and formulae for this purpose. There is a special material on the market which is known as 695 Plastic; that is the commercial name. I suppose the base of i t is chrome. I t just about doubles the life of our tapholes. Ordinarily we were running around 15 to 18 heats. We have increased that to about 23 heats. That is where we are making a varied line of product, high- carbon and low. The maximum has gone a great deal beyond that. We have found this plastic to give excellent service on iron mixer spouts, as well as in tapholes. I t is.undoubtedly the best material I have tried yet.

CHAIRMAN R~I~~nTz . -Anyone else? I forgot to ask Mr. Spence about the practice of the Sore1 Steel

Foundry Co. in regard to basic linings of ladles.

MR. SP~Nc~.-During the past few years. there has been a great improvement in steel quality, due to a reduction of non-metallic inclu- sions as.the result of better furnace practice. Therefore, i t would seem ~ h a i ' further? progress would be made if the pick-up of non-metallic. i:mpurities froin.the.lad16 lining could be rzduced.also.

Tapping a basic steel and a basic slag into an acid-lined ladle does not appear to be metallurgically sound. Several years ago fairly extensive tests on basic linings were carried out :at one large steel plant. Antici- pated improvements in steel quality resulted, but mechanical difficulties with the lining were encountered.

Electric furnace operators, particularly those pouring higll-manganese steel such as Hadfield's steel of 12 to 14 per cent manganese content, impose very severe conditions when on acid ladle linings: The work with basic slag was, therefore, continued in this industry and a plastic, basic wash was finally secured which gave marked improvement.,

3

When No. 695 Plastic Cement was developed for open-hearth furnace maintenance, we recognized that its properties were such that it should make a' good basic ladle lining. Bearing in mind the progress already made in electric-furnace steels, this material was offered to that industry

. as a basic ladle lining Results e r e immediately reported as being excellent. The advantages were twofold:-

(1) The ladle lining life was increased from 3 to 5 times over previous average practice.

(2) Non-metallic impurities were largely eliminated, as shown directly by decreased rejections.

Since that time a number of similar producers have used this material continuously and, lately, a small stainless-steel producer, formerly having experienced difficulty with .acid ladle linings, has used this material with very good results.

The material as marketed is a dry mix with necessary bonds incor- porated. I t is tempered with water to a definite consistency and rammed behind a form directly against the ladle shell. After slow drying to drive out all moisture, followed by further heating to a dull red, the lining is ready for service.

CHAIRMAN REINARTZ.-YOU have no idea as to how that lining would work on low-carbon rimmed steel, have you?

MR; SPENCE.-NO, but the electric furnace steel service just described is more severe than any other practice in so far as erosion of the lining is concerned, both because of the high steel temperature carried and the sharpness of the slag. As an indication of'the severity of service encoun- tered,several operators were obtaining a life of only two to three heats to the lining; this has now been increased to a maximum of twenty-five.

MR. TRANTER.-Who makes that material? CHAIRMAN R ~ ~ ~ ~ ~ ~ z . - C a n a d i a n Refractories Co. MR. MCDONALD.-I certainly would not recommend iutting mag-

nesite against the shell of a ladle. I t conducts heat very rapidly. There should be some brick--between'it and the shell of the ladle.

I

CHAIRMAN REINARTZ.-T~(: s~lggestion was made last night that if onc put about an inch of insulation next to the shell, that would take carc of the extra heat lost from the basic lining.

Mr. Fitterer expected to be here to discuss the use of his thermo- couple in ladle practice. I received a telegram from him this morn- ing, instead.

chair ma?^ Reinartz read a telegram jrom Mr. Fitterer.

CHAIRMAN REINARTZ.-Has anyone here tried 'the Fitterer thermo- ,couple? It has been tried in several Steel Corporation plailts, I am told, but I do not know whgther our independents have tried it or not.

The next is: "Two-stopper ladle-where used? Size heats. What results?

What kind of nozzles? Any changes for differbnt grades of steel pro- duced? Does the improvement in quality or ingot yield ofiset increased installation and maintenance cost?"

The first man t o put in a two-nozzle large ladle, I 'believe, was our friend, Mr. McKune. What is your practice with two-stoppers? .-

MR. F. B. MCI<UN;.-W~ are still using twd stoppers very success- fully, and with very satisfactory results.

CHAIRMAN REINARTZ.-Mr. Ramsey, are you still using two nozzles? , MR. RAMBEY.-We use elliptical ladles with two nozzles, and I can

verify what Mr. McKune has said. We feel we have dbtained a better surfaceaon the ingot and there is less variation in temperature from the time you start teeming until you stop: It also has a benefit upon the interior of the ingot. We believe it has benefited us materially. We are -

increasing our two-stopper ladles as quickly as business permits. CHAIRMAN'REINARTZ.-H&VC we anyone else here using the ~ ' W O stop-

per rods in the ladle?

MR. MERcun.-We are using two stoppers. In fact, we used them years and years ago. Then we had to stop because of a change in our mechanical equipment. But we are pouring almost all of our steels now with two nozzles.

CHAIRMAN REINARTZ.-DO YOU use two nozzles from the quality standpoint? '

MR. ME~cun.-From quality, because we can control the temperature ranges much easier. We can hold the heat in the ladle a little longer if

desired. We believe tlie illcreased quality more than offsets the extra cost.

CHAIRMAN R E I N A R T Z . - A ~ Y O ~ ~ else?

MR. MCCUTCHEON.-O~~~ thing in connection with the use of two stoppers I think is of importance. After pouring ten or eleven 5-ton ingots of dead-soft steel the nozzle is badly cut. Up until then you find the time of pouring the ingot is decreasing. From then on the time is decidedly increasing. If you put two nozzles in the ladle, the heat is practically poured by the time you, pour ten ingots out of each. So you are able to get the slowest pour possible with the given nozzle before the lrcat is out of the ladle.

Also we have found, in pouring these very low-carbon heats with one stopper, we had difficulty with the stopper heads. 'With the equipment we were using the bolt would melt and the head would come off by the time we had poured twelve or thirteen ingots, if we drained the way we would like to drain. By this method of pouring with two nozzles, we have no stopper trouble at all. I think tlle decided improvement in quality more than offsets the added cost.

CHAIRMAN R E I N A R T ~ . - A ~ ~ O ~ C else? "Is basket pouring being used in any plants? How many nozzles in

basket? What results?" Can anyone give us an answer? Does anyone use basket pouring

a t all? MR. MCKIMM.--W~ used it, but eliminated it about two years ago.

We now use single nozzles; and have a very deep ladle. CHAIRMAN REINARTZ. -T~~ Otis ladle looks like a cylinder instead

of a ladle. . MR. MCKIMM.-I would like to ask a question. Mr. Tranter told

about the large nozzle. .What do you find to be the most suitable llozzle size?

MR. TRANTER.-OI~~ with an opening about 2 inches in diameter. MR. M c K r ~ ~ . - w e found. the 1%-inch was better, on a 150-ton

heat. ' We adopted i t after using for some timc 2-inch and 25i-inch round nozzles and an oval nozzle measuring approximately 13i by 2ja inches. With the smaller nozzle we have less difficulty with scabs and obtain a better wall and better segregation. That is, the carbon held up about 0.01 higher than formerly or with the 1arger.nozzles.

' CHAIRMAN REINARTZ.-"HOW to avoid leaky nozzles when using graphite nozzles and stopper heads."

Has anyone ever tried a nozzle which had some graphite in i t ? MR. MCCUTCHEON.-I believe we reported some years ago we used a

nozzle that was half graphite. One half of it was strongly impregnated with graphite and the other half was clay. This was not satisfactory. I do ilot think that is an arraignment of a graphite nozzle, but the ones we tried were certainly not satisfactory.

MR. BELLEVILLE.-The Joseph Dixon Crucible Co. has done a little along the lines of developing a nozzle, the top half of which is clay and the bottom half of which is graphite; but we have not gone far enough in the development of that particular scheme to speak authoritatively about it.

CHAIRMAN REINARTZ.-YOU have a clcaner stream from a graphite nozzle when i t does work.

MR. BELLEVILLE.-T~~~ is thc thought back of this whole scheme, and 'we llopc to work that o i ~ t a littlc later.

CHAIRMAN REINARTZ.-L1~ow to avoid the contamination of steel by material sloughed. off nozzles .of bottom-pour ,ladles."

MR. M c K u ~ ~ . - w e use an "outside" stopper which might be of some value. I have a print of it with me arid I will put it on the board. This is a very cheap apparatus and it is very efficient. You can make it for $5.

MR. SCOTT.-I would like to know if this nozzle arrangement would keep chip brick out of the way from the slabs. We have a lot of trouble with small particles of brick in 'the surface of our slabs.

CHAIRMAN REINARTZ.-YOU mean part of the ladle brick chipping off and getting into the steel?

MR. SCOTT.-I want to knbw if that will take care of it. I do not know whether i t came from the nozzles or some other place.

CHAIRMAN REINARTZ.-Mr. McKune, Mr. Scott finds chips of ladle brick in his ingots a t times and wants to know whether your practice will prevent that. Do you think it comes from the nozzle or the ladle itself?

MR. McKuNE.--I do not know that it will prevent that, but i t will prevent a lot of other things.

MR. SCOTT.-DO YOU get more chips of brick and inclusions in slabs from bottom pour than from top pour?

MR. McKuNE.-W~ use bottom pour, for special steel, and we have to watch the brick.

MR. SCOTT.- he question 1 want to ask now is: Do you think yot~. get it from the runner brick or from the nozzle?

MR. MCKUNE.-I think it comes from the runner brick used in bottom pouring. You have to watch that.

CHAIRMAN REINARTZ.-NOW we will go to mold practice: "What are the main components of ingot mold design from the stand-

point of quality of ingot? Mold life?" We have a little controversy sometimes on that subject, but I am

going to ask some friendly enemies to discuss this subject. I am going to call on Mr. Gathmann first.

Ingol; Mold Practice alld ~ 6 s i ~ r l

MR. E M I ~ GATHMANN.-Most of the members of the Open-Hearth Committee appreciate that the highest grades of steel are today made

- from ingots cast in big-end-up molds provided with shrinkheads or hot- tops. Despite the superiority of such ingots, compared 'with those cast in big-end-down molds, the big-end-up ingot of today still falls short of perfection and presents opportunities for further advancement.

In this connection, reference is made to the quicker cooling of the lower part of the ingot, obtained by the use of massive copper plugs or stools suitably armored or sheathed with a ferrous plate employed in closing the bottom opening of the mold. '

a. The salient requirements of an ingot mold for producing any type of steel is that the mold shall provide for solidification of the ingot from the bottom upwardly to as great a degree as practical; and that the cross section of the mold be such that the skin of the ingot is free to con- tract inwardly without undue stresses, as such stresses frequently cause rupture or seams in the ingot.

b. As we,all know, the useful life of molds, or rather the number of ingots that can be produced in the several units of a jag of molds, varies considerably. I t is quite common to obtain a long life of say 100 ingots from some molds, while other molds in the same jag fail a t 50 or less. For this reason, the average life of molds a t many plants is relatively poor. This difference can not all be accounted for by variations in foundry practice or mold iron analyses. We believe some of the primary reasons for great irregularity in mold life to be, in order of their importance:

1. Allowing the ingots to remain in the molds longer than is necessary. 2. Positioning the molds too closely to one another on the cars. 3. Permitting the molds to remain in the same relative position on thc

cars for numerous successive heats. Ingots should be separated from physical contact with the molds-in

killed hot-topped steel as soon as possible after solidification is complete, and in rimming steel as soon as the top of the ingot is well frozen over.

I t must be borne in mind that the mold iron has only a limited capacity for heat absorption, and that the more heat units i t is forced to absorb unnecessarily from an ingot, by just that amount is its life shortened.

c . In killed steel production a 26-inch &ton ingot should be allowed to remain in the mold about 4 hours. In rimming steel production it should remain from 40 minutes to an hour, and then immediately charged into reheating or soaking pit.

d. The length of ingot compared to cross-section is primarily deter- mined by the ability to teem a small-cross-section ingot, without the

nlolte~l strcam of stccl impacting on thc walls of the mold chamber. Tlle actual ratio of length compared. with cross-section in slab molds or in square molds, from a metallurgical point of view-primarily from one of solidification of the ingot-is not the important factor. There is a definite height or length for all ingots, irrespective of cross-section, beyond which it is not, safe to go. This height is somewhat less for slab than for square ingots and should, in our opinion, not exceed 65 inches in slab or 75 inches in square mill ingots, unless the ingot is bottom poured, or top poured exceedingly slowly. The ferro-static pressure of the molten ingot metal minus the rate of ingot skin solidification is the main consider- ation as to how high an ingot can be poured.

e. Due unquestionably to the fact that big-end-up molds can now be handled economically in the production of ingots without shrinkheads, no single subject has been in for more discussion among many steelmakers during the 'past several months than the use of big-end-up molds for rimming steels. Numerous tests have been conducted, with all sorts of results in yields and quality of product. One plant has made some 50,000 tons of rimming and semi-killed steel ingots in big-end-up molds without being able to come to any conclusion regarding their advantages. I shall attempt to point out some of the reasons why results have varied to such a degree.

j. "Any" big-end-up mold will not do. Rimming steels can be suc- cessfully produced in big-end-up molds only if certain definite relative dimensions as to taper, height and cross-section of mold are employed. Because a specific design has been successful in producing killed stccl ingots with shrinkheads, i t sllould not be inferrcd that that design will be satisfactory in production of rimming ingots.

The ingot mold should be of limited height compared with its cross- section so that the ferro-static pressure of the molten mass will not be sufficient to deter the motion inside the lower half of the ingot shell. I n the average size rolling mill ingot, the height should not exceed about 65 to 72 inches. We have found further that a straight or a substailtially straight section in the upper portion of the mold, for 15 to 25 per cent of its volume, is usually necessary to produce a rim without undue rise.

The temperature of the molds when teemed, as also of the temperaturc of the molten steel, have great bearing on the quality of the ingots. Thc temperature of all molds of a jag should be substantially uniform. To have some molds hot, some cold and others in-between is to invitc non- uniformity in the quality of the surface of ingots from the same hcat. A cold mold will almost invariably cause pitting of the ingot surface and near-skin blowholes.

I t is obvious that the bottom of the mold should be necked-in so that

the 'ingot will. roll without fishtailing. The bottom 'crop from blooms rolled from well-designed big-end-up ingots.need not exceed 1 per cent of the volume of the ingot. This means an increase in ingot-to-bloom yields of a t least 3 per cent over the usual crop llecessary from the bottom of big-end-down ingots.

Another advantage of a well-designed big-end-up mold in rimming steel production is the ability of steels of higher carbons to rim success- fully. Steels of 0.15 to 0.20 per cent carbon, which caknot be rimmed in big-end-down molds, have been rimmed satisfactorily in big-end-up molds.

The most important desideratum in making quality rimming ingots is, of course, good surface. This is assured where correct designs of big- end-up molds are employed, because there is closer and longer contact between mold and forming ingot, and a relatively thick skin or shell of physically sound steel forms before the interior molten mass has cooled appreciably and become pasty. I n addition, the big-end-up co~ltour prevents any well-defined shrinkage cavity or pipc from forming in the upper portion of the ingot.' The photograph of a half-section of a 4-ton 0.09 per cent carbon ingot shows how deeply the blowholes are . located, and why the surface of blooms, billets and finished product from ingots of this type are superior.

Big-end-up molds recommend themselves to the steelmaker on many counts, particularly because of improved surface and greatcr yields. The specific design of mold must, however, be adapted to fit the requirements.

g. Suitably corrugated molds'are useful in the production of all types of ingots, as properly corrugated contours lend themselves to the shrink- age or contraction of the skin of the ingot without producing undue stresses, seams or open cracks in this initial skin.

h. For top pour the best rate of rise of steel in the molds is, in our experience, the same in rimming and killed steels. Pouring should be a t a rate which insures the formation of substantial initial skin thicknesses immediately below the top of the surface of the growing ingot. Rate of pour, without knowledge of temperature of steel above the point of solidification, is an incomplete factor.

i. From a number of tests made under ,our supervision during the past twelve months, we have found that bare copper stools are apt to be cut and eroded quite rapidly by high-carbon steels, especially steels made by the acid process. As to low-carbon steels, we have. no per- sonal experience.

The advantages of copper stools (or rather plugs) can be obtained in cooling ingots of any analyses without danger of cutting the copper by placing a relatively thin plate of steel upon the copper stool to take the first impact of the teeming stream. We have made a large number of tests with copper stools thus reinforced with steel plates of from % to

inch thicknesses, in various sizes of molds, producing ingots of from one to &ton weights; and have invariably found that a copper stool properly protected is not cut or eroded and wil1,last practically indefinitely. In four molds, recently tested, producing 5%-ton ingots, eighty-some heats were made per mold and the copper stools were in the same physical condition after these heats as when they were first used. The steel plate employed to protect the copper welds to the bottom of the ingot, and a new plate is used for each ingot.

Aside from increased mold life, the primary advantage of a copper stool is obviously its ability to extract heat from the central portion of the bottom of the ingot. In analysis of split ingots made in this manner, we have found that the steel is much denser and less segregated in its longi- tudinal core portion than when the~plugs or stools were made of cast iron.

CHAIRMAN REINARTZ.-Have YOU anything to say on this subject, Mr. Bradley?

MR. BRADLEY.-I think it has been very nearly covered. Mr. Gathmann has left little for me to say, but I can possibly make a few .

suggestions about mold wall thickness. We have found that an ingot mold which has excessively heavy wails

will give a comparatively short useful life, on account of a pronounced tendency toward early fire-cracking or what is commonly known as alligator checking, and the resultant ingot surface will be poor.

Molds with walls that are too thin are apt to fail before a normal life has been obtained, on account of major cracks starting usually a t the bottom and working upward. Such molds give a good ingot surface but tend somewhat to increase segregation in the ingot, due to slower absorp- tion of heat.

Repeated tests in Germany as well as in this country have proved that there is little or nothing'to be gained by going to extremely heavy or light walls and tha t a mold should be so designed that i t will show major cracks only after theinner surface hasdeteriorated to such an extent that further use is no longer advisable.'

To avoid splitting, extreme slab-type molds must of necessity be made relatively heavier than square or round molds and an increase in the pounds of molds per ton of steel is the inevitable result.

CHAIRMAN REINARTZ.-Mr. Kauffman, have you anything to add? MR. KAUFFMAN.-I have nothing to add to what the gentlemen have

said 1~110 have so adequately discussed this subject. I thank you very much for the opportunity, however.

MR. W H I T E . - I ~ ~ O ~ molds and chill molds that I have had experience with, carried from 1.70 to 2.00 per cent silicon, the higher silicon being taken more or less from the German practice. In the past few years we have tried a lower silicon, such as 1.10 to 1.20 per cent, and I believe the lower silicon has increased the life of the mold, due to less fire cracking occurring on the low-silicon molds.

MR. REINARTZ.-HOW high was the manganese content? MR. WHITE.-0.60 to 0.70 per cent. MR. REINARTZ.-H~V~ you anything to tell us about the Fitterer

thcrmo-couple?

MR. WHITE.-Yes, 1 believe we used the first couple in service a t our plant, and we are using it now. I think the couple has a future if i t is handled right.

In most plants we have metallurgical control and the temperature of the heat is usually read with some sort of an optical pyrometer, and a time given for holding the heat or going ahead. If the Fitterer couple temperature is taken just before you start to pour a heat, and these temperatures recorded, you will find, after a certain number of heats are poured, that this instrument is nearer correct and will hold to a closer line on the temperature of t11e respective compositions of steel poured than most instruments used a t present. We are now taking freezing points on our various grades of steel and from these we will work back to a satisfactory pouring temperature; which, in my opinion, is any tempera- ture which gives a consistent practice resulting in good product.

CHAIRMAN REINARTZ.-Does anyone have any ideas on this, or any questions to ask Mr. White? Do you know how much it costs to install?

MR. WHITE.-I do not know a thing about the price. That is up to the sales department.

CHAIRMAN REINARTZ.--Mr. McDonald, have you tried basket- pouring?

MR. MCDONALD.-We tried basket pouring twenty years ago and discoiltinued it.. We used it then to prevent piping and segregation. Today we are using it to prevent ingots from cracking in the rolls. I t gives a thicker skin on the ingot. It is something like bottom pouring. I t brings the ingots up slower and gives the skin a chance to thicken.

On two ingots we poured through the basket there were no cracks; in the rest of the heat, which was poured direct, there were quite a few cracks in rolling.

1935 OPEN-HEARTH CONFERENCE MINUTES ., 3 7.

CHAIRMAN REINARTZ.-we will go back to our mold design question. How about some of these practical operators telling us something about their experience with different kinds of molds?

Mr. Walters, you are here now. MR. J. D. W A L T E R S . - T ~ ~ ~ is what we call a burning question. We

have found that a lot depends on the kind of mold. We ask about the big-end-up mold. Personally, I do ~ i o t think it mkans a thing. I will tell you why. When'you pour steel you have the cooling effect of the bottom plate plus the mold. Until it opens up and starts to rim, whether it is 2 inches, 6 inches, 8 inches or 10 inches determines whether you have secondary blowholes.

When we .get it, we find that from where the metal opens up and starts to rim it is all right; but from the time we start to pour until it opens up we have a double line of blowholes.

The bigger the volume,' of course, the lower the pouring temperature. If you pour 10 inches a minute, it is quite different from 20 inches a minute. If you pour 10 inches a minute, you, will find it will open beauti- fully. I t is an imprdvemint; there is no.question about it.

We have a definite ruling that we will not pour less than six 21 X 42, 21 X 48, 16 X 42 or 20 X 42-inch ingots on bottom plate, because we know definitely what will happen if we pour less. When we do we invariably get what we call spongy bottoms on our ingots, and a splashy condition on bottom of ingots. We have proved that conclusively. Every time we get back and check it up and find that they have pourcd four ingots, instead of six or eight, and it rises too fast.

The evidence is concrete. I t has been proved by practical results. We have attempted to work out a formula on mold design; Mr. Bradley will bear me out. I would be glad to have i t in the minutes so anybody can get any use from it he wants. We have a definite design for a definite purpose and we have proved i t conclusively.

In other words, a mold is designed with a too-round edge on the side. We can prove that to be poor design. The squarer you can make the edge, the better results will follow.

. At this time I want to give Mr. Faithful of the Central Iron & Steel Co. credit for a tip hi! gave me. I do not know how many of you know it, but I want to tell you it means something. In bottom-pouring 80 ingots or 16 ingots to a plate, or whatever you have, Mr. Faithful told me if you put boards one inch thick or 2 inches thick down over the outlets it prevents splashing and surging and it makes a wonderful difference. That is exactly what happens. If you dissipate the pressure and gases evenly over the mold walls, you get a smooth ingot surface. I want to give him credit for this tip.

COATESVILLE, ' PA. .

SLAB-INGOT CONTOUR AND DESIGN Revised June 20, 1934

Ends of Ingot THICKNESS

Up to 11% inches 12 inches to 13% inches 14 inches to 17% inches 18 inches to 19% inches 20 inches to 22% inches 23 inches to 25% inches 26 inches to 28% inches 29 inches to 31% inches 32 inches to 3474 inches 35 inches to 37% inches 38 inches to '40% inches

MILL TREATMENT both Universal and Plate Mill. . . . . . . . . . flat both Universal and Plate Mill. . . . . . . . : . inch rise both Universal and Plate Mill. . . . . . . . . % inch rise both Universal and Plate Mill. . . . . . . . % inch rise Plate Mill only. . . . . . . . . . . . . . . . . . . . . . . 1% inches rise Plate Mill only.. . . . . . . . . . . . . . . . . . . . . . l 3 i inches rise Plate Mill only.. . . . . . . . . . . . . . . . . . . . . . 2 inches rise Plate Mill only.. . . . . . . . . . . . . . . . . . . . . . 2% inches rise Plate Mill only.. . . . . . . . . . . . . . . . . . . . . . 2% inches rise Plate Mill only.. . . . . . . . . . . . . . . . . . . . . . 23i inches rise Plate Mill only.. . . . . . . . . . . . . . . . . . . . . . 3 inches rise

Sides of Ingot Up to 2514 inches wide.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . no camber 26 inches wide to 39% inches wide.. . . . . . . . . . . . . . . . . . . . . . . . . . . inch camber 40 inches wide to 59% inches wide.. . . . . . . . . . . . . . . . . . . . . . . . . . . inch camber 60 inches wide to 90 inches wide.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 inch camber

Corner Radius of Ingot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 inches to 93.8 inches thick. . 1 inch radius-

10 inches to 14% inches thick.. . . . . . . . . . . . . . . . . . . . . . . : . . . . . . 1% inches radius 15 inches to 19% inches thick. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 inches radius 20 inches to 25% inchcs thick.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2% inches radius

. 26 inches to 307.8 inches thick. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3% inches radius 31 inches to 3574 inches thick.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 inches radius 36 inches to 40 inches thick and over . . . . . . . . . . . . . . . . . . . . . . . . . 43i inches radius

Taper on Ingot - Thicl~ness-1 inch in 60 inches or less of length-for all thicknesses (% inch per foot)

Width-1 inch in 60 inches or less of length for ingots up to 20% inches in width. inch in 60 inches or less of length for ingots 21 inches to 3974 inches in

width. W inch in 60 inches or less of length for ingots over 40 inches wide.

Increased proportionately for ingots over 60 inches long.

General . In redesigning molds according to this Schedule, please note:

1. Mean area according to new design is to be held same as previous mean area. 2. On Universal Mill molds, hold present width and vary thickness to suit. 3. On Plate Mill molds, hold present thickness and vary width to suit.

Thickness of Ingot-Maximum dimension of short side at bottom end. Width of Ingot-Maximum dimension of long side a t bottom end. Length of Ingot-Total available length in ingot mold. Rise on End and Camber on Side--One-half the amount of increase in thickness or

width over what i t would be if the ingot had flat sides and ends. Taper on Ingot-Total change in thickness or width.

So far as I am concerned~personally, anything I can give or anything I can do which will help somebody else, I am tickled to do. I want to be as frank as I can be. If I can give a pointer, I am going to do i t per- sonally. When anyone comes to my shop, I am going. to tell him just as nearly as I can the truth. If you go into a man's shop and he tells you he is melting for less than 35 gallons of oil to the ton of ingots, you want to

\ Bottom End

. . A = W i i B = Rise C= Th/ckness D = CamberoE =Corner md4us

DESIGN BASIS FOR SLAB MOLDS, AS USED B Y LUKENS STEEL COMPANY.

feel that he is telling the truth. There is no argument. That is just the attitude you like to feel toward him. You come here and spend a lot of money that belongs to your company. Maybe they are not financially able to spend the money, but are willing to do their bit to help.

We make a pretense of helping one another. We come here and tell a lot of lies; perhaps not intentionally, but we have no proof. Now if it is worth my effort to come to Cincinnati, it is worth my effort to tell you the truth, and I am going to do it. If we are doing a certain thing, we can not stop you from doing it if you want to do it, and sooner or later you are going to do it the same as we are. So what is the use of bucking the issue? If we can improve the product, we should do it. That is the attitude you have to take. Why shouldn't we tell them? There is no reason why we shouldn't.

If we went into war tomorrow, what would we do? We would help each other produce enough shells to lick the other fellow-mold design, pouring rate, anything we could do in defense of our country. I t did come and it is going to come again.

We are either kidding ourselves or coming here trying to get every- thing the other fellow has and giving nothing in return.

Take our rolled steel. Regardless of our slag or whatever might hap- pen, we do not get duplicate results. There is a reason. One heat will be just perfect. Another heat will be exactly the same. Still there is a difference in results. .We have with us Dr..Hill; everybody knows him.

We are working on slag control and believe we have obtained some definite results. We are as willing as can be to give any information or help to anyone. That is why weare here. If we did not have that attitude we would not be here. I do not know; he does not know; we will try to find somebody who does know.

We do know definitely, gentlemen, that any effort we can put forth is well worth while. We are sure of that. There is no argument about it. How we do things is another question. If you know better than I do, it is one member to another. That is the attitude here today. (Applause)

CHAIRMAN REINARTZ.-The second question: . L L Has anyone used aluminum as a mold wash for rimming or killed

steels? How mixed? How applied? " 1. What kinds of mold coating used on rimming steels or killed

steels? d

"2. Is mold coat changed for different size ingots?" MR. KIT TO.-^^ u%e it on molds for killed steel-about two-thirds of

a pint of pulverized aluminum, about eight quarts of the bronzing liquid-and apply it with a brush. We do not use i t for rimming steel.

MR. J. D. WALTERS.-We have used aluminum paint. We like i t very much. We are securing aluminum powder or paste from a paint company in New York, and we use aluminum heat-resistant oil. I believe we get that from the same people. We mix that, 1f.i pounds of aluminum powder base to one gallon of oil. We find i t very beneficial. We do not use it on everything. I t is all done on alloy steel, high-carbon steels. I t is better on oxidized killed than on open steel.

CHAIRMAN R E I N A R T Z . - W ~ ~ ~ do you uFe when making rimming steel?

MR. WALTERS.-We do not use anything at all. We have tried it, but can not satisfy ourselves on it.

CHAIRMAN REINARTZ.-Mr. Bower. MR. BowER.-We use tar. We have used it for years on all kinds and

grades of steel and different molds. We try to have the molds so they are about 200 degrees F.

MR. SCHUELER.-We use tar on all of our molds, for both killed and rimming steel.

MR. E. D. BUCHANAN.- We do not use anything on molds, but we tar the stools.

MR. R E I L L Y . - ~ ~ use tar on all our molds. MR. SHANNON.-We llse graphite. MR. ALBAUGH.-We Use graphite on most grades of steel. MR. ICING. -We use tar, and we dip the mold.

MR. MACISAAC.-We use tar on hot-topped high-carbon forging steel. We have also tried aluminum on high-carbon steel, but used in a different way. I t was powdered aluminum which we mixed with foundry molasses and water, and applied with a brush; but we did not see that i t helped us.

MR. MILLS.-We do not use any mold wash. We make both rimming and killed steels.

MR. MERCUR.-I would like to make a suggestion. Aluminufi has no heat-resisting properties and has no particular advantages. as a coating. I am wondering if the men who are using it have in mind a mix- ture of aluminum oxide. I would make that suggestion, a mixture with about 40 per cent oxide, plus aluminum.

MR. C L I F F O R D . - - T ~ ~ ~ ~ is one thing that might be helpful to anyone n7ho is coi~templating the use of tar for mold wash. We have foui~d there is a very definite relation between success in the use of tar and the corner radius of the mold. In other words, tar is not successful on molds with a large corner radius, because corner cracks result.

MR. TRANTER.-We found the same thing happened a t Middletown. MR. R A M S E Y . - ~ ~ use tar and we dip our molds in:the tar tank.

As the gentleman just said, we had some trouble with corncrqcracks, due to a large radius. After reducing that radius, we got away from corner cracks.

MR. B R A D L E Y . - G ~ ~ ~ ~ ~ ~ has for some time advocated asphalt lacqucr for mold coating. I would like to ask if anyone here is using it.

CHAIRMAN REINARTZ.-H~S anyone tried asphalt lacquer? Mr. Buck, what is your practice? MR. BUCK.-We use no mold wash whatever.

RIMMING HEATS. IN BIG-END-UP MOLDS

CHAIRMAN REINARTZ.-MT. Gathmann told you about rimming heats poured into big-end-up molds. Has any operator here had any experience in pouring rimming heats into big-end-up molds?

MR. SHANNON.-We tried it a few years ago, and found a very much increased yield. We used the regular big-end-up mold we ordinarily use for high-carbon killed steels.

CHAIRMAN REINARTZ.-YOU did not change the design? MR. SHANNON.-NO. We got increased yields and better surface.

On one heat we had actually 94 per cent yield. MR. BRADLEY.-I might say that the molds in which that steel was

poured had a straight section. To get good results in rimming steel, a straight section is necessary, and was incorporated in the mold.

MR. MARK GATHMANN.-We have been running tests of fifty heats in a large plant in the Pittsburgh district. The first seven heats we averaged

better than 6 per cent gain over the big-end-down molds. We were making low-carbon rimming steel. The highest carbon on the test was 0.10 per cent.

MR. FONDERSMITH.-W~~~ Was the basic yield from ingot to bar started from, on which the 6 per cent increase was figured?

CHAIRMAN REINARTZ.-HOW much yield did you have on the big- end-down molds before you began figuring your 6 per cent?

MR. GATHMANN.-I can read you these different yields on the seven heats, if you wish to take thc time.

CHAIRMAN REINARTZ.-Was that steel supposed to be cropped clear of pipc?

MR. GATHMANN.-YCS, in both lots. We have 14 molds, 22 by 24 inches, with straight 16-inch scction a t the top, with regular Gathmann coiltour a t the bottom. Both ingots wcighcd exactly the same.

MR. EMIL GATHMANN.-May 1 make this onc rcmark? The trouble with big-end-up rimming ingots is that there is no way to get them out of the mold. That factor we believe has started the Morgan people working on it.

MR. MERCUR.-Wc have been using the Gathmann mold big-end-up ingot ever siilcc thc Gathmann mold came out. In fact, we have poured rimming steel in big-end-up molds for many years.

CHAIRMAN REINARTZ.-H~V~ you any different taper on the mold from what you would have used on killed steel poured into big-end-up molds ?

MR. M~ncu~ . -Same taper, with a straight section upon the top. MR. McCuTc~~oN.-What is the idea of the straight section a t the

top? Why is it necessary? MR. EMIL G A T H M A N N . - O ~ ~ ~ ~ W ~ S ~ therc would be an excessive rise of

the molten metal before thc rimming action begins. If we could by some practical means actually slightly contract the cross-section of the ingot a t its uppcr end, and still maintain a big-end-up contour in the lower and body portion, wc could produce an ingot with improved interior soundness as wcll as improved skin or surface of the ingot. In other words, the rimming action occurs sooner if we have a straight section a t

the top of the chamber than if we have a continuous big-end-up contour to the top of the mold.

In a standard big-end-up or simply inverted mold, the rise is usually excessive before rimming action begins; me have tried this many times and there is invariably a higher rise when the big-end-up contour con- tinues to the upper part of the mold. Such ingots behave likc a wild heat rather than like those of the true rimming type. With a big-end-up straightrtop mold chamber of suitable proportion, we obtain only 1?$ to 3 inches rise of the molten steel before the rimming action is completed and the ingot is ready for capping. I have here a photograph of a rim- ming steel ingot thus produced, which I will pass around.

CHAIRMAN REINARTZ.-I would like to ask a question. Mr. Mercur, did you have to change your deoxidation practice when changing from pouring rimming steel in big-end-up to big-end-down molds?

MR. MERCUR.-NO; we used the samr addition. CHAIRMAN RE1NA~~z.-Anyone else? MR. J. D. WALTERS.-Not trying to kill Mr. Gathmann's salcs talk,

not a bit, but you have to go by facts. I am allo~ved on bottom pour what they measure or think they can get from still iron. Evidently if I pour big-end-up over big-end-down, you can readily understand I have to give them an inch on each ingot. The better thing for me to do is to give a less area rather than a greater. I have to give them so much, maybe 3 per cent, to assure them they are going to get the plate they desire out of that ingot. If I use the big-end-up, I have to give that much more metal.

With regard to yield, I cannot see how it would affect the ultimat,e result. If you have a perfectly rimmed heat, 6-inch skin or 4-inch skin, I admit i t will rim longer with the big-end-up rathcr than the big-end- down, but if you take the actual weight of ingot, what difference does i t make?

MR. GATHMANN.-I think Mr. Walters misconst.rues my statement. I am absolutely in favor of bottom-pouring rimming steels if i t can be done economically, but the expense as far as I am informed is usually prohibitive in most plants using car pra.ct,ice. What I said was not in any manner a reflection on bottom-pouring but a description of an improved mold for ingot formation of rimming steels for t,oppouring car practice.

MR. FONDERSMITH.-C~~ Mr. Gathmann get the molds big enough, whether 12 slabs or whatnot?

MR. GATHMANN.-We have not tried the slab molds as yet, to any extent.

MR. F O N D E R ~ M I T H . - H ~ ~ ~ you tried 12 size molds? MR. GATHMANN.-Yes, i t works all right.

CHAIRMAN REINARTZ.-" What results using copper stools?" Mr. Clyde Williams, have you anything to say on that subject?

Annual Report on Copper Stools MR. CLYDE E. WILLIAMS.-The use of copper stools has continued

during the year. There is not a great deal to add beyond wha,t we said last year. Steel plants have continued to get increased heats from properly-made stools, particularly on rimming steels.

FIGURE 1 .-COPPER STOOL AFTER 80 HEATS.

1935 OPEN-HEARTH CONFERENCE MINUTES 45

Stools made from high-conductivity copper by the col)l)er refincries, and of suitable size, have givcn good rc~sults. Where high-conduclivity copper has been used there has been an absence of cutting of the stool or sticking of the ingot to the stool in every case where the stool has been of proper weight in relation]Ito the ingot. I t has been more effective to gain additional weight by increasing the thicl<ncss rather tha,n the area.

The first stool is still in use; i t has gone something over 1500 heats, 600 on one side and 900 on the other.

To get the maximum life out of copper stools, they should be made flat, so they can be used on each side.

A few slides will illustrate the checking of the surface, which is similar to the characteristic heat-checking common to iron ingot molds. These checks begin to form after about 100 heats and continue to grow. The checking can be stopped by peening as soon as the checks appear.

A FIGURE 2.-COPPER STOOL AFTER 600 HEATS.

We do not know what the life will be of stools made of the proper kind of copper and of the correct weight. This one stool is perhaps a little heavier than one that would be used normally, which accounts for its exceptionally long life.

Figure 1 shows the first stool used, after 80 heats. It is large enough to take two 24-inch square ingots. The first few heats were made with

FIGURE 3.-COPPER STOOL AFTER 1500 HEATS; 600 OW BOTTOM, 900 ON TOP.

one mold placed in the center of the stool. You will observe the heat checks in the center.

Figure 2 shows the same stool after 600 heats, most of which were poured with two molds on the stool. At this stage the cracks had become large enough so that t,he ingot began to stick. The stool was then turned over and has been used on this side for over 900 heats, shown in Figure 3.

Figure 4 shows a stool which was cast flat in a plant where normally only one side of the stool is used. The copper stool was made flat on both

sides and bolts were put in to act as guides to replace the lugs, so that either side of the stool cor~ld be used.

That stool is used for a large mold, rectangular in shape, which nearly covers the stool. At the time this picture was takcn the stool had been used for 150 to 175 heats. The checking in this one is considerably less than in the first one, which had gone less than 100 heats. I think the reason these checks are shallower is because the plant occasion&lly peens the cracks-whenever t,hey become large enough to look serious.

FIGURE 4.-COI'PER STOOL WITH BOLTS A S GUIDE FOR MOLD

In some of the early trials on a rectangular-shaped mold a crack appears right across the center of the stool. This was corrected by mak- ing thicker stools. The failure presumably was a concentration of st,resses there, caused by contraction and expansion. However, to permit this expansion and contraction, one of the copper companies has devel- oped a laminated stool. That stool consists of a number of flat cakes of copper placed on edge inside of a cast-iron frame. The cakes are held in position by two springs a t one end. Those springs are protected from shove by a cast iron shelf. Any tendency to form a crack is prevented by the movement of the cakes. In other words, the cakes can pull apart without the metal itself having to crack. The contacts between the cakes remain so close that no steel runs in between thc cakcs. Figure 5 illus- t,rates the laminated stool.

This type of stool will be especially advantageous for large, rectangular- shaped ingots.

I

One of the things which has been a little difficult to understand about the use of copper stools is the increased life of the mold. In comparative tests iron molds used on copper stools have lasted very much longer (in one case twice as long) than iron molds used on iron stools. M y concep- tion of the increased mold life is that the steel is cooled more quickly if i t washes over the copper stool, which absorbs heat tmen times as fast as

Cost iron frame

FIGURE 5.-LAMINATED COPPER STOOL IN CAST I R O N FRAME.

iron. Thus the ingot cools faster, especially in its lower section, and the air gap between the ingot and the mold wall forms more quickly and prevents the transfer of heat directly to the mold as fast and for as long a time as is the case when an iron stool is used.

We made a few measurements of the temperature in a cast iron stool and a copper stool, used under large rectangular molds and placed side by side so as to get steel a t equal temperatures. When the thermo-couple was placed right where the stream struck the stool, and as close to the surface as possible without actually piercing it, the maximum temperature in the iron stool reached a t that point was about 800 degrees F. and on the copper stool about 500 degrees F.

MR. SCHUELER.-IS there any difference between the iron stool and the copper stool in cases where the bottom of the steel is air-cooled?

MR. WILLIAMS.-YOU mean if the stool were sitting on a car wllere you would havc it air-cooled? . . MR. SCHUELER,.-yes-the difference between stools on cars, where they would be subject to air-cooling, and those standing directly on the ground and which would not be air-cooled.

MR. WILLIAMS.-W~ have no information on a copper stool that was uscd on the ground floor; but I do not believe it would cause any difficulty, because the copper removes heat from the steel so rapidly that freezing of the steel takes place before the copper stool absorbs all the heat i t can. So radiation or conduction of heat away from the copper stool is not of great importance, if the stool is thick enough.

MR. M c C u ~ c ~ E o ~ . - W h a t is the best relation between ingot rate and stool rate?

MR. WILLIAMS.-The best ratio-is from 1 to 156 steel ingot to 1 cop- per stool.

MR. MC~UTCHEON.-What do you mean when you say "high-con- ductivity copper?"

MR. W 1 ~ ~ 1 ~ ~ s . - N i n e t y , to 100 per cent. The copper refineries produce. copper of about 100 per cent conductivity. The ordinary high-conductivity copper made by brass foundries and deoxidized with zinc or silicon or manganese is much lower than this, usually 35 to 50 per cent, even though a small amount of deoxidizing agents are used. , The high-conductivity copper produced by the copper refineries is nearly purc copper, containing about 0.04 per cent oxygen. I t is cast into water- cooled metal &olds to avoid formation of gas pockets or spongy areas.

CHAIRMAN REINARTZ.-Mr. Edward R. Williams, have you a few remarks on use of copper for stools?

Further Results on the Use of Copper for Inserts in Ingot Mold Stools

MR. EDWARD R. WILLIAMS.-At last year's Open-Hearth Committee meeting, in Pittsburgh, a number of points were discussed in connection with the usc of copper in stools and inserts. During the past year many additional tests have been made to check these previous results and conclusions. This paper is intended as a progress report and the results are given under similar headings.

Ratio of Mass of Copper to Ingot. The following cxperiments have been made to determine what effect mass of copper has on the cutting of the copper.

TestNo. (I) Ingot size 14% X 34% X 69 inches. .Weight 7400 pounds.

Insert size 2254 X 4146 X 10 inches. Weight 1890 pounds.

Ratio ingot to insert weight 3.9 to 1. 50 heats of rimming steel were poured. Result-

No cutting. The same insert was poured with all conditions the same, except with

silicon steel about 100 degrees F. colder. Result-Cut very badly. Test No. (2) Ingot size 14 X 1655 X 54 inches. Weight 2990 pounds.

Insert size 1855 X 21 X 9 x 6 inches. Weight 740' pounds.

Ratio ingot to insert weight 4 to 1. dbout 100 heats of rimming steel were poured on several inserts.

Result-No cutting. These same inserts were poured with all conditions the same except 0.70 per cent carbon steel about 100 degrees F. colder. Result-Cut badly, 80 per cent of time. When nozzle was opened very slowly until mold partly filled there was no cutting.

Test No. (2A) Test No. 2 on difference between high-carbon steel and rimming steel was repeated using a copper stool, 26 X 26 X 4 inches, weight 800 pounds, ratio 3.5 to 1; 'and also a copper stool, 26 X 26 X 8 inches, weight 1600 pounds, ratio 1.75 to 1. Result-Same as for the lighter copper insert. The high-carbon stecl cut nearly every time, while the rimming steel did not.

Test No. (3) The following test was made with electric-furnace alloy steel. Ingot size 7>/4 X 744 X 43 inches. Weight 470 pounds. Insert size 1 0 x 6 X 1 0 x 6 X 4 inches. Weight 100 pounds. Ratio ingot to insert weight 4.7 to 1.

Result-No cutting. The bottom of the insert was then machined off successively 1 inch in thickness until i t was only 1 inch thick, and weighed 50 pounds, with ratio of 8.9 to 1. About five ingots were poured each time an inch was cut off. Result-No cutting a t any time.

Conclusion-From these tests i t is concluded that ratio of mass of ingot to copper is not a factor in the cutting or welding of the copper. Much more experience will be needed to determine the most economical weight of the insert for the conditions involved.

Composition of Steel Being Poured. The above results indicate that the chemical composition of the steel may be a factor in the cutting. To determine whether chemical reaction takes place between the oxygen in electrolytic copper and the carbon, silicon or alloys in the steel, a copper stool made of oxygen-free copper was tried on test No. 2A above. ' Result- The same cutting by high-carbon. steel was found as with the electro- lytic copper.

Length of T i m e of Contact between Molten Stream and Copper. I t was noticed that when the ladle nozzle was opened slowly, to give time for a pool to form, cutting was usually eliminated. A test the same as No. 2 above with high-carbon steel was made on an insert which had previously cut, except that the steel was poured through a pouring box. Result- No cutting.

Conclusions :- The pouring box apparently reduced the ferro-static head enough so

that the stream did not penetrate so far through the molten ingot, and so did not wash the copper for a sufficient period to raise its temperature to a welding point.

Possibly the same result could be accomplished with a larger nozzle, which would fill the mold quicker and cut down the time of contact. This, however, presents an operating problem when speed of ingot pouring must be governed. Apparently some grades of steel, such as high-carbon and silicon, are more fluid than others, such as rimming steel, allowing the stream to penetrate to a greater depth and washing the surface of the .

copper stool for a longer period when all other conditions are equal. Steels like rimming steel freeze more rapidly than those like high-

carbon, and possibly form a better protecting skin against the copper stool, which is not remelted by the stream.

Conductivity of Copper. No conclusive tests have been made to determine how the conductivity affects cutting, but apparently it is not an important factor.

There have not >et been sufficient stools i n d inserts scrapped to give definite results. Providing failure does not occur by cutting or welding, the following factors seem important :-

Composition of Copper. This should be' as near 100 per cent conduc- tivity as possible, which is obtained from electrolytic or oxygen-free copper. If copper is deoxidized with phospl~orus, fire cracking may occur earlier.

M a s s of Copper. The maximum temperature which is reached by the stool or insert probably determines the degree of fire cracking. The proper weight of copper to balance its life against cost must be found by further experiments.

Proper Treatment. The fire cracks which form in the copper must be closed a t intervals by peening. Pneumatic hammers provided with a round-headed tool are being successfully used, and this treatment pro- longs the life of the copper materially.

No adverse effects have been reported on any tests made so far. The following benefits have been reported by the use of dished copper inserts:-

Loss on th~e butt end of big-end-up ingots due to cracking has been rcduced to nearly nothing, compared with a loss of from 2 to 5 per cent on plug-bottom molds. On big-end-down molds, the crop loss due to fins, scabs, "fish-tailing," and "manufactured pipe," on rimming steel has been rcduccd to practically nothing, compared with from 2 to 5 per centd loss from flat cast iron stools.

Ingot defects from splashing have been reportcd rcduced by a t least 60 pcr cent.

On ccrtain grades of electric-furnace steels, thc surface porosity on the butt end of the ingot has been completcly eliminated.

Thcsc bcnefits have been obtained because the dish in the inscrt is so shaped that the steel does not splash against the side of the mold, and because it does not weld to the copper to cause cracking.

I

Rcsults must be divided into two classes as follows:- Molds failing by cutting a t the bottom:-Life has been increased by

from 10 per cent to 400 per cent by permitting these molds to fail normally by fire cracking.

Molds failing by fire cracking:-No conclusive tests have been made. A somcwhat grcater amount of heat is absorbed from the ingot by copper than by a cast iron stool or the bottom of plug bottom molds, which thus rcquircs thc mold to absorb less heat. The relief is not sufficient, how- ever, to rcducc the fire cracking of the mold materially. No grcat increase in mold life is expected from this standpoint. \

Additional advantages on dished copper insert and cast iron stool assembly have been reported from an improved design. Pads have been added on the insert, stool and mold, which are chipped to templets and pcrmit centering of the dish in the insert with the inside of the mold. Thcrcforc, onli a very narrow ledge a t the butt end of the ingot is formed, which will not lap over when rolling or forging.

Cast iron inserts instead of copper have been furnished to steel com- panies for rimming steel and other grades that cut only slightly. A life of over 200 heats has been reported, and with excellent results from the standpoint of improved ingot quality. The copper inserts may, however, be found more economical in the long run.

Dished copper inserts show economy both in reduced mold or stool cost and also in ingot cost, by impi.oving steel quality and yield.

A large ratio of mass of copper to ingot is not necessary to prevent cutting or welding of the copper.

1935 OPEN-HEARTH CONFERENCE MINUTES 53

Some changes in operating practice may be necessary to prevent the cutting of copper on certain grades of steel or under certain conditions.

Further experiments for particular conditions will be necessary to determine the most economical weight of copper insert.

CHAIRMAN REINARTZ.-Our time is up for the morning session. I have a very intcresting lettcr received about a day ago from Russia, from Mr. Ralph Vaill, who has attended our mectings quite a number of timcs:

" Mr. Reinartz : "Thanks for notice. Can't make it this year. Giving the Siberians

the benefit of what I learned in previous attcndance your meetings. Will try to forward to you prior to session somc of the problems which con- front the Russians, as to my mind they are novel problcms to us Ameri- cans. But havc a good rnceting, be curious, throw away conservatism and investigatc all aspects of our work, for thcse fellows are so doing.

"They arc skeptical of American practice. They are not satisficd with German technic. They are trying to wean themselves away from their old German-Russian technic. They study night and day. They try anything once. They are developing metallurgically a t an astounding rate. Seventy thousand tons last month from ten furnaces, and a Siberian winter to fight every hour. Ten-hour heats (and not bad ones) from 150-ton furnaces, using an 80 per ccnt iron charge.

"Good luck. " R. VAILL."

I thought you would be interested in that letter. . . . T h e session adjourned at 12:35 p. m. . . .