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British Steel

SectionsPlates &CommercialSteels

Scunthorpe Rod MillPO Box 7, Brigg Road,Scunthorpe, North Lincolnshire, DN161BQ

M

OurRef: pd6635

Mr. I. P. N. JohnsonKTS Wire IndustriesPark MillsSouth StreetMorleyWest YorksLS27 SAT

Dear Ian

Tel: (44) 01724 404040Fax: (44) 01724 282656 Sales Fax: (44) 01724 381438

2nd August 1999

PD 6635 - Non-allov steel rod for drawing and/or cold rolling

As you may be aware, BSi has issued a "Published Document" with the above title.

You will no doubt recall the background to this document. Following the publication in 1995 ofthe European Standard for Wire Rod (BS:EN10016, Parts 1 - 4), it was widely felt that thestandard did not fulfil the requirements of the UK wiredrawing industry, particularly in respectof surface quality (maximum defect depths), the facility to order high carbon steel to tensilestrength ranges, and one or two other parameters. Under the auspices of UK Steel, a WorkingGroup, representing both the wiredrawing and rod rolling sectors, was set up to address theseissues. The end result, after numerous discussions and drafts, is PD6635. Please accept theenclosed complimentary copy.

The obvious intention now is that PD6635 should be widely used, and should replace - over aperiod of time - customer in-house specifications. During the course of the next few weeks, theCustomer Technical Support team and I will be in contact with you to offer assistance andadvice on any aspects of this transition process where you may envisage difficulty.

In the interests of economy (PD6635 costs 18 per copy - no discounts, not even for BritishSteel!!), you are the only recipient of this letter within your company. I should be grateful ifyou would make its contents known to those of your colleagues who need to be aware.

If you have any questions or comments in the meantime, I will be pleased to try to answer them.

Many thanks for your co-operation.

Yours sincerely

J. H. BODDYBritish Steel picRegistered Office: 9 Albert Embankment, London, SE1 7SN

l in Tn/ilanH Kin

11PUBLISHED DOCUMENT

Non-alloy steel rod for drawingand/or cold rolling Generalpurpose rod, rimmed andrimmed substitute low carbonsteel rod, rod for specialapplications Requirementsand tests

ICS 77.140.60; 77.140.65

NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW

PD 6635:1999

IIPD 6635:1999

Committees responsible for thisPublished DocumentThe preparation of this Published Document was entrusted to Technical CommitteeISE/71, Steel rod for wire drawing, upon which the following bodies wererepresented:

Process Plant AssociationUK Steel AssociationWelding Manufacturers' Association (BEAMA Ltd)

This Published Document, havingbeen prepared under thedirection of the EngineeringSector Committee, was publishedunder the authority of theStandards Committee and comesinto effect on 15 March 1999

11PD 6635:1999

Contents

PageCommittees responsible Inside front coverForeword m1 Scope 12 Normative references 13 Terms and definitions 13.1 heat analysis 13.2 product analysis 14 Classification and designation 14.1 Classification 14.2 Designation 15 Production process 26 Common requirements 6.1 General6.2 Internal soundness and surface quality for all types of rod 26.3 Inspection of non-metallic inclusions 26.4 Method of delivery 26.5 Delivery condition 27 Requirements for general purpose rod 27.1 Chemical composition and mechanical properties 27.2 Depth of surface defects and soundness 27.3 Core segregation 28 Requirements for rimmed and rinuned-substitute low-carbon steel rod 28.1 Chemical composition and mechanical properties 28.2 Depth of surface defects and soundness 29 Requirements for rod for special applications 29.1 Chemical composition and mechanical properties 29.2 Depth of surface defects and soundness 29.3 Core segregation 39.4 Depth of decarburization10 Dimensions, mass and tolerances 311 Inspection and testing 311.1 Inspection and inspection documents 311.2 Extent of inspection 311.3 Acceptance unit and number of samples and test pieces 311.4 Test of chemical composition 311.5 Test of decarburization, surface defects, non-metallic inclusions and core

segregation 311.6 Test methods 312 Marking 3Annex A (normative) Determination of core segregation 9A.1 Scope 9A.2 Definition 9A.3 Principle 9A.4 Preparation of samples 9A.5 Evaluation of the segregation 9Annex B (informative) Information to be supplied by the purchaser 11

ItPD 6635:1999

FigureA.1 Five classes of segregation 10Tables1 Chemical analysis (heat analysis) for general purpose rod 42 Chemical analysis (heat analysis) for rimmed and rimmed-substitute low

carbon 53 Chemical analysis (heat analysis) for rod special applications 54 Permissible deviations in the product analysis in relation to the actual heat

analysis for general purpose rod 55 Mechanical properties for general purpose rod and rod for special

applications 56 Limit values for the depth of surface discontinuities for general purpose

rod 6

7 Permissible deviations in the product analysis in relation to the actual heat |-analysis for rimmed and rimmed-substitute low-carbon steel rod 6

8 Tensile strength values for rimmed and rimmed-substitute low carbon steelrod 6

9 Limit values for the depth of surface discontinuities for rimmed andrimmed-substitute low-carbon steel rod 6

10 Permissible deviations in the product analysis in relation to the actual heatanalysis for rod for special applications 7

11 limit values for the depth of surface discontinuities for rod for specialapplications 7

12 Limit of the depth of partial decarburization 713 Extent of inspection 714 Acceptance unit and number of samples and test pieces 8

IIPD 6635:1999

Foreword

This Published Document has been prepared by Technical Committee ISE/71. It isderived from BS EN 10016 Parts 14, with the data being presented in a singledocument, and with the addition of mechanical properties. The publication of this PDis necessary because UK practice in the steel wire industry differs from that in the restof Europe; particularly the practice of specifying mechanical properties rather thanchemical composition. It is anticipated that the publication of this PD will assist in thepreparation of the UK view for the revision of EN 10016.Compliance with a Published Document does not itself confer immunityfrom legal obligations.

Summary of pagesThis document comprises a front cover, an inside front cover, pages i to iv, pages 1to 11 and a back cover.

PD 6635:1999

1 Scope1.1 This Published document is applicable to thefollowing types of non-alloy steel rod:

a) general purpose rod for drawing and/or coldrolling;b) rod of low carbon, low silicon, rimmed andrimmed-substitute steel with high ductility fordrawing and/or cold rolling;c) rod with improved characteristics intended fordrawing and/or cold rolling.

NOTE The cross-section of the rod may be round, square,rectangular, hexagonal, half-round or another shape and as ageneral rule of nominal size 5 mm or above (see EURONORM17):the >urface is smooth.

1.2 It is not applicable to the following products forwhich standards exist or are published such as:

steel rod intended for heat treatment(see BS EN 10083 and 10084 and EURONORM 85and 86); rod of free-cutting steels (see BS EN 10087); steel rod for cold heading and cold extrusion(see EURONORM 119); steel rod intended for the production ofelectrodes and products for welding (seeEURONORM 133); steel rod for welded fabric for reinforcementfor concrete (see DD ENV10080); steel rod for wire for high fatigue strengthmechanical springs, such as valve springs.

1.3 In addition to the requirements of this standardthe general technical delivery requirements specifiedin BS EN 10021 apply.

2 Normative referencesThe following normative documents containprovisions which, through reference in this text,constitute provisions of this part of this PublishedDocument For dated references, subsequentamendments to, or revisions of, any of thesepublications do not apply. For undated referencesthe latest edition of the publication referred toapplies.BS EN 10002-1, Metallic materials TensiletestingPart 1: Method of test (at ambienttemperature)BS EN 10020, Definition and classification of gradesof steelBS EN 10021, General technical deliveryrequirements for steel and iron and steel products.BS EN 10027-1, Designation systems for steel Part 1: Steel names : Principal symbols.BS EN 10027-2, Designation systems for steel Part 2: Steel numbers.

BS EN 10052, Vocabulary of heat treatment terms forferrous products.BS EN 10079, Definition of steel products.BS EN 10204, Metallic products Types ofinspection documents.BS EN 10221, Surface quality classes for hot rottedbars and rods Technical delivery conditions.EURONORM 171), General purpose rod of non-alloysteel for drawing Dimensions and tolerances.ISO 3887, Steel, non-alloy and low alloyDetermination of depth of decarburization.ISO 14284, Steel and iron Sampling andpreparation of samples for the determination ofchemical composition.DD ENV 10247, Micrographic examination of theinclusion content of steels using pictures.

3 Terms and definitionsFor the purposes of this Published Document thefollowing definitions apply in addition to thedefinitions of ISO 14284, BS EN 10020, BS EN 10021,BS EN 10052 and BS EN 10079.3.1heat analysischemical analysis representative of the heatdetermined by the steelmaker at his discretion hi amanner of his choice3.2product analysischemical analysis carried out on a sample of thedelivered product

4 Classification and designation4.1 ClassificationThe classification of the steel grades defined bychemical composition covered by this PublishedDocument according to BS EN 10020 is indicated hiTables 1, 5 and 9 for the corresponding steel grades.4.2 Designation4.2.1 Steel namesFor the steel grades defined by chemicalcomposition covered by this Published Document,the steel names as given in Tables 1, 5, and 9 areallocated in accordance with BS EN 10027-1.4.2.2 Steel numbersFor steel grades defined by chemical compositioncovered by this Published Document the steelnumbers as given in Tables 1, 5 and 9 are allocatedin accordance with BS EN 10027-2.

PD 6635:1999II

5 Production processThe steelmaking and fabrication processes shall bemade known to the purchaser. Those processes thatare specifically agreed shall not be changed withoutprior agreement of the purchaser.

6 Common requirements6.1 GeneralThe manufacturer is responsible, using whatevermeans thought fit for inspecting the production fromthe point of view of the various quality criteriaspecified. In view of the fact that it is impossible inpractice to inspect coils of rod apart from at theends of the coils delivered, it cannot be proved thatv^/alue greater than the specified limits is to befound in the coil as a whole.NOTE Statistical evaluation of performances applicable to allcoils may be agreed between the purchaser and the manufacturerat the time of ordering.6.2 Internal soundness and surface quality forall types of rodThe rod shall have no internal and/or surfaceimperfections such as: shrink holes, segregation,cracks, folds, incrustations, notches, scabs, rollingbuns, damage, which could be prejudicial to itscorrect use.6.3 Inspection of non-metallic inclusionsThe method for inspecting non-metallic inclusionsand the assessment criteria for it shall be agreed atthe time of ordering, as far as possible withreference to DD ENV10247.6.4 Method of delivery""s products shall be delivered by heat or part of a* jt The number of heats per delivery shall beminimized as far as possible.6.5 Delivery conditionRod shall be supplied in the as-rolled state, in coilsof one continuous length with non-aligned turns, butcapable of being unwound in a regular mannerduring subsequent processing. The coils shall be cutback at both ends to provide a product of uniformshape and properties.

7 Requirements for general purposerod7.1 Chemical composition and mechanicalpropertiesFor grades specified by chemical composition, thevalues shown in Table 1 apply. The permissibledeviations of the product analysis relative to theactual heat analysis are given in Table 2. At therequest of the purchaser at the time of ordering, themanufacturer shall notify indicative values of tensilestrength. For grades specified by tensile strength, thevalues cYmwn in TnHlo 3 armlv

7.2 Depth of surface defects and soundnessThe rod shall not have any surface discontinuities ofdepth greater than the values shown in Table 4. Therelevant classes shall be agreed at the time of orderand enquiry. These limit values apply for the testchosen in accordance with 11.5.1 and 11.6.2.7.3 Core segregationIn the absence of other provisions the followingrequirements shall be met By agreement at the timeof ordering, rod of steel grade C60D or steel gradeswith higher carbon content shall be inspected forcore segregation. Not more than 10 % of the samplesshall be of class 4; class 5 is not allowed (seeannex A). It is recommended to do this evaluation aspart of a quality assurance system.

8 Requirements for rimmed andrimmed-subsitute low-carbon steel rod8.1 Chemical composition and mechanicalpropertiesFor the heat analysis, the values shown in Table 5apply. The permissible deviations of the productanalysis in relation to the actual heat analysis aregiven Table 6. Unless otherwise specified at the timeof ordering, rod of diameter 5,5 mm and above shallhave the maximum tensile strength values shown inTable 7.8.2 Depth of surface defects and soundnessThe rod shall not have any surface discontinuities ofdepth greater than the values shown in Table 8.These limit values apply for the test chosenaccording to 11.5.1 and 11.6.2.

9 Requirements for rod for specialapplications9.1 Chemical composition and mechanicalpropertiesFor grades specified by chemical composition, thevalues shown in Table 9 apply. The permissibledeviations of the product analysis relative to theactual heat analysis are given in Table 10. At therequest of the purchaser at the time of ordering, themanufacturer shall notify indicative values of tensilestrength. For grades specified by tensile strength, thevalues shown in Table 3 apply.9.2 Depth of surface defects and soundnessThe rod shall not have any surface discontinuities ofdepth greater than one of the classes shown inTable 11. The relevant class shall be agreed at thetime of order and enquiry. These limit values applyfor the test chosen according to 11.5.1 and 11.6.2. O

ItPD 6635:1999

9.3 Core segregationIf so agreed at the time of enquiry and order, rod ofgrade C60D2 or grades with a higher carbon contentshall be inspected for carbon segregation. Not morethan 5 % of the samples tested shall be of class 4;class 5 is not allowed (see annex A). It isrecommended to do the evaluation as part of aquality assurance system.9.4 Depth of decarbarizationThe specifications given below concerning the depthof decarburization and the inspection procedurerelating to it apply only to grades C42D2 to C98D2.9.4.1 Complete decarburizationThe rod shall not display complete decarburization.9.4.2 Partial decarburizationThe rod shall not display partial decarburization ofdepth greater than the values given in Table 12. Themaximum point of decarburization shall not exceedtwice the limit of Table 12. These limit values areapplicable to the test described in 11.5.2.

10 Dimensions, mass and tolerancesThe dimensions, mass and tolerances of the productsshall be in accordance with the requirements ofEU17.

11 Inspection and testing11.1 Inspection and Inspection documentsThe provisions of BS EN 10021 and BS EN 10204shall apply.11.2 Extent of inspectionIf the order is accompanied by a request for aninspection certificate, the inspection shall be carriedout in accordance with Table 13.11.3 Acceptance unit and number of samplesand test piecesThe acceptance unit is composed of rod of the samediameter or equivalent dimension, originating fromthe same heat and rolled as a single continuous lotunless otherwise agreed. If specific inspection isrequired the number of test pieces in Table 14 shallapply.NOTE For rod for special wire applications a higher frequency ofsampling may be agreed If the non-specific inspection is requiredthe performance statistics or suitable data may be used.11.4 Test of chemical compositionWhere it has been agreed to verify the chemicalcomposition on the product, the samples shall betaken and prepared in accordance with ISO 14284.11.5 Test of decarburization, surface defects,non-metallic inclusions and core segregation11.5.1 For testing for surface defects, totaldecarburization, non-metallic inclusions and coresegregation, the test pieces shall be taken from oneend of the wormed mil fc ft K\

11.5.2 Testing for decarburization shall be carriedout on the rod in the as-rolled condition, inaccordance with ISO 3887 with the followingexceptions.Decarburization is inspected by a microscope on atransverse metalloagraphic test piece suitably etched,with a magnification of X 200. The depth ofdecarburization of the sample is considered as beingthe average of 8 measurements at the endsof 4 diameters located 45 to each other, startingfrom the zone of maximum decarburization. Startingfrom a defective zone shall be avoided. In thecalculation of the above average value, anymeasuring point of the seven remaining situated in alocal surface defect shall not be taken into accountin the calculation.11.5.3 For the determination of non-metallicinclusions and core segregation, the tests shall becarried out on the rod in the as-rolled condition andin accordance with 6.4, 7.3 and 9.3.11.6 Test methods11.6.1 Test of chemical compositionThe methods to be applied for the verification of theproduct analysis shall be agreed at the time ofordering, with reference to existing EuropeanStandards, where these are available. Forarbitrational analyses, the methods shall be thesubject of agreement between the parties concerned.11.6.2 Test for surface defectsThe method to be used for revealing surface defectsshall be chosen by the manufacturer.11.6.3 Tensile testThe tensiletest should be performed on rod in theas-rolled condition, in accordance withBS EN 10002-1.11.6.4 Test for core segregationThe method for determining the core segregationshall be by macrographic examination on atransverse section of the sample as specified inannex A

12 MarkingEach coil in each consignment shall be marked withthe following information:

dimensions of the cross-section of the rod; designation of the steel grade; cast number, manufacturer's name and symbol; any subsequently agreed information.

The marking shall withstand pickling. The durabilityof the labels utilized for marking shall be agreed atthe time of ordering.

PD 6635:1999 It

Table 1 Chemical analysis (heat analysis) for general purpose rod1)2)Steel grade3)

Steelname

C4DC7DC9DC10DC12DC15D

PD 6635:1999

Table 2 Permissible deviations in theproduct analysis in relation to the actual heat

analysis for general purpose rodElement

C

SiMnPandS

Steel grade

C4D to C20DC26D to C82DC86D to C92DAll gradesAll gradesAll grades

Permissible deviationin product analysis

%

0,020,030,040,040,060,005

Table 3 Mechanical properties for generalpurpose rod and rod for special applications

Steel grade

T700T750T800T850T900T950T1000

Ultimate tensile strengthB

NAnm2

650/750700/800750/850800/900850/950900/1000950/1050

Table 3 Mechanical properties for generalpurpose rod and rod for special applications

(continued)Steel grade

T1050T1100T1150

Ultimate tensile strengthRm

NAnm2

1000/11001050/11501100/1200

Carbon content shall be selected by the manufacturer to achievethe specified properties. Other major elements shall be asfollows:-

Si 0.10-0.30%Mn 0.50 -0.80%S 0.030% max.P 0.030% max.

The specified properties apply to a mean value of atleast 5 samples taken from each cast or batch

Table 4 Limit values for the depth ofsurface discontinuities for general purpose

rodClass

Inm

UatHmnm surface defectdepth (K of nominal rod

diameter) measuredradially

4.03.02.0

Table 5 Chemical analysis (heat analysis) for rimmed and rimmed-substitute low carbonsteel rod1)

Steel grade2)Steelname

C2D1C3D1C4D1

Steelnumber

1.11851.11871.1188

Heat analysisC

max

0,030,050,06

Si

max.

0,050,050,10

Mn

0,20-0,350,20-0,400,20-0,45

P

max.

0,0200,0250,025

S

max.

0,0200,0250,025

Cr3)

max.

0,100,100,15

max

0,100,100,15

Mo

max.

0,030,030,03

max.

0,100,150,15

A14>

max.

0,010,050,05

N

max.

0,007

1} Elements not included in this table should not be added intentionally to the steel without the agreement of the purchaser, except

those intended for finishing the cast3 Special non-alloy steel according to EN 1002035

The sum of the contents Cu + Ni + Cr shall not exceed: for steel grade C2D1, 0,25 %; for steel grade C3D2, 0,30 %; for steel grade C4D1, 0,36 %.

4) For steels grade C3D1 and C4D1 a lower maximum limit should be specified at the time of ordering.

6) Boron, up to a level of 0,010 % may be specified at the time of ordering.

PD 6635:1999

Table 9 Chemical analysis (heat analysis) for rod for special applications1)2) (continued)Steel grades3^Steelname

C78D2C80D2C82D2C86D2G88D2C92D2C98D2

Steelnumber

1.12521.12551.12621.12651.12721.12821.1283

Heat analysisC

%

0,76-0,800,78-0,820,80-0,840,84-0,880,86-0,900,90-0,950,96-1,00

Si

%

0,10-0,300,10-0,300,10-0,300,10-0,300,10-0,300,10-0,300,10-0,30

Bin5)

%

0,50-0,700,50-0,700,50-0,700,50-0,700,50-0,700,50-0,700,50-0,70

P

96max.

0,0200,0200,0200,0200,0200,0200,020

S

%max.

0,0250,0250,0250,0250,0250,0250,025

Cr)

%max.

0,100,100,100,100,100,100,10

Ni

96max.

0,100,100,100,100,100,100,10

Mo

%max.

0,020,020,020,020,020,020,02

Cu6)7))%

max.

0,150,150,150,150,150,150,15

Al)

96max.

0,010,010,010,010,010,010,01

Nio)

96max.

0,0070,0070,0070,0070,0070,0070,007

l) Elements not included in this table may not be added intentionally to the steel without the agreement of the purchaser, except those

intended for finishing the cast3 The addition of microalloying elements can be agreed between the manufacturer and purchaser at the time of ordering.' Special non-alloy steel according to EN 10020.4)

For rod intended for galvanization the allowed lower limit of silicon content should be specified at the time of ordering. For the manganese content, a different range from the one indicated in the table can be agreed at the time of ordering with amaximum value not exceeding 1,20 96 and with an amplitude of 0,20 96.9

The sum of the contents Cu + Ni + Cr shall not exceed 0,30 96.7>Cu+SnsO,1596.* For certain applications the Cu content may be restricted to 0,12 % max. by agreement9)

By agreement at the time of ordering, the value for aluminium can be fixed at 0,02 to 0,06 96. The value for silicon can then be fixedat 0,10% on request10)

If, in accordance with note 9), the Al content is fixed at 0,02 to 0,06 96, the limit value for N shall be agreed at the time of ordering.

Table 10 Permissible deviations in theproduct analysis in relation to the actual heat

analysis for rod for special applications

Table 12 Limit of the depth of partialdecarbnrization

Element

C

SiMnPandS

Steel grade

C3D2 to C20D2C26D2 to C82D2C86D2toC98D2All gradesAll gradesAll grades

Permissibledeviation in product

analysis %0,020,030,040,040,060,005

Noniitftl divnftter rfw nunn5 < dN ss 88 < dN = 30

Limit values mm0,10!,2%ofdN

Table 13 Extent of inspection

Table 11 Limit values for the depth ofsurface discontinuities for rod for special

applicationsClass

IVV

Maximum surface defect depth (%of nominal rod diameter) measured

radially1.51.0

Type of test

Surface defectsDecarburizationNon-metallicinclusionsCore segregationProduct analysisTensile strength

Generalpurpose

rod(clause?)

00

000

Lowcarbon

steel rod(clauses)

+

-

0

-

00

Bod forspecial

applications(clanseS)

+

+

0

000

+ = carried out- = is not carried out0 = is only carried out if part of the options and/oris agreed at time of ordering

ItPD 6635:1999

Table 14 Acceptance unit and number of samples and test piecesType of requirement

Product analysis

Permissible depth of surface defectsPermissible depth of decarburizationNon-metallic inclusionsTensile strengthCore segregation

Number of samples or test pieces3, from 3 different coils originating from the sameheat, but not necessarily rolled as a singlecontinuous lot

1 for every 20 tons with a minimum of 3

10

PD 6635:1999

Annex A (normative)Determination of core segregationA.1 ScopeThis annex is applicable for rod made fromcontinuously cast steel with a carbon content of atleast 0,40% C and defined in this Published DocumentThe method described further is a macrographicmethod aimed at determining and evaluating the coresegregation present in continuously cast high carbonrod by revealing the carbon segregation.A.2 DefinitionFor the purpose of this standard, the followingdefinition applies.A.2.1 Core segregationCore segregation is the local variation in chemicalcomposition which can be noticed over a cross-sectionof rod by macrographic examination. It concernsprimarily the segregation resulting from thesteelmaking process. This segregation takes placeconcurrently for many elements: carbon, phosphorus,manganese, sulfur, etc. This is the reason why we canexamine core segregation by revealing specifically thecarbon segregation. Grain boundary cementite, whichis particularly influenced by the thermal history of therod (from liquid steel to rod) and of its size can alsocause problems in further processing. This justifies theuse of specific methods for evaluating the presence ofgrain boundary cementite, which is related to carbonsegregation, but not be confused with core segregation.A.3 PrincipleThe chemical heterogeneity is revealed by chemicaletching of a cross-section of the rod in a nital solution,the images observed by macrographic examination arecompared with the pictures of the reference chart andclassified accordingly.A.4 Preparation of samplesA.4.1 CuttingThe surface to be examined is a transverse section ofeach sample to be examined. This is obtained bygradually cutting at low speed In any case excessiveheating is to be avoided by appropriate cooling.

A.4.2 PolishingThe sample is first polished stepwise, whereby thefinishing will be carried out with diamond paste offinal grain size 1 um. After mirror polishing the sampleis carefully washed with water and dried in alcoholA.4.3 EtchingThe polished surface is etched at ambient temperaturein the nital solution during about 10 seconds. The nitalsolution is a solution of 2 ml of nitric acid(20 = 1,33 g/ml) in 100 ml of ethanoL After etching thesurface is dried in alcoholA.5 Evaluation of the segregationThe etched surface is observed with a binocularmicroscope with illumination under a small angle witha magnification so as to obtain about the samedimension as for the reference pictures. The pictures inthe chart are limit references for each class concerned.Actual pictures are compared, positioned and gradedwithin the reference chart They obtain the class of thereference picture equal or worse than the pictureunder observation.AJS.l Classes of segregation

Class 1: without segregation zoneClass 2: core segregation with slight contrast (mediumgrey)Class 3: core segregation with medium contrast (darkgrey)Class 4: core segregation with pronounced contrast(small black core)Class 5: core segregation with heavy contrast (bigblack core).A.5.2 Evaluation of the test resultsIt is generally accepted that a large number of resultsis required for a statistically significant evaluation ofthe core segregation of a cast or a shipment The valueof the assessment of the core segregation on anindividual sample has only a relative value. For thisreason and for limiting the number of tests to aneconomically acceptable level it is advisable to use thedetermination of the segregation a part of a qualityassurance system.

PD 6635:1999II

Figure A.1 Five classes of segregationo

illPD 6635:1999

Annex B (informative)Information to be supplied by thepurchaserThe following information should be supplied by thepurchaser at the time of enquiry and order.

a) quantity to be delivered;b) product denomination (rod);c) cross-section (round, square, hexagonal, etc);d) reference to the dimensional standard;e) nominal dimensions;f) reference to this Published Document;g) steel name or steel number (see 4.2);h) dimensions and mass of coils;

.

i) surface condition (where different from the -as-rolled condition),j) where applicable, indication of the type ofdescaling (chemical or mechanical);k) where applicable, the type of inspection andinspection document in accordance with EN 10021and EN 10204 respectively (see 8.1);1) where applicable, the method of binding andlabelling;m) where applicable, if the steel grade shall besuitable for galvanization;n) where applicable, suitability for direct drawing;o) where applicable, suitability for patenting.

ItPD 6635:1999

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