bhushan-traioning-report-
TRANSCRIPT
SUMMER TRAINING REPORT
TO STUDY VARIOUS OPERATIONS OF COLD ROLLING MILL
SUBMITTED BY:
GAURAV PANDEY ISHU
MECHANICAL ENGINEERING
3rd YEAR (0816140016)
KRISHNA ENGINEERING COLLEGE GHAZIABAD
Bhushan Steel Ltd.
CONTENTS
1 Introduction
2 Acknowledgement
3 Company Profile
4 HRS
5PICKLING LINE
6 ELECTROLYTIC CLEANING LINE
7ANNEALING
8SKIN PASS MILL
9FINISHING
10 ROLL GRINDING MACHINE
11GP 1
12GP 2
13SAFETY
14RESEARCH & DEVELOPMENT
15QUALITY SYSTEM
16CONCLUSION
INTRODUCTION
This entire report deals with the study of the various operations conducted in
NCRM (New Cold Rolling Mill) in order to manufactured the products like cold
rolled sheets, galvanized coil etc. during the entire period we deals with the
various processes that are involved in the manufacturing of the above mentioned
products.We visited departments like HRS, SPM, RGM, GP-1, GP-2 etc. where the
various operations are conducted involved in the production of CR coils,
Galvanized coil. The machines and equipment’s used are of higher standard and
norms which are imported from the JAPAN, GERMANY and other countries in
order to maintain the accuracy and precision as well as to produce good quality
products.The working environment of the company is excellent, technicians and
workers are highly skilled.They work hardly to develop standards products and
achieving the goals of the company. Workers are trained by the company to update
their knowledge and skills.
Finally it’s really a great learning experience for me while working in the BSL,
SAHIBABAD. This training helps me to learn the basics of the industrial work and
other relevant factors which work as the stepping stone of my professional life. I
am thankful to each and every one who is involved in my work and all the officials,
technicians and workers which help me to learn a fruitful lesson from the working
environment of the BSL, SAHIBABAD.
ACKNOWLEDGEMENT
This summer training is stepping stone towards the beginning of my professional
carrier and its satisfactory has endowed me with broader horizons of knowledge. This
training period is a fruitful culmination of my concerned affords during my summer
training at Bhushan Steels Ltd. Sahibabad.
I would like to express my thanks to Mr. Manish Jain (personal) for given me an
opportunity to a part of this esteemed organisation. I would like to express my deep
sense of gratitude to the entire workers and technicians of NCRM (New Cold Rolling
Machine) department. Especially the HOD’s of various departments of NCRM for their
inspiring guidance, continuous encouragement and valuable suggestion.
At last but not the least, I would like to thank all personnel of Bhushan Steels Ltd, who
are directly or indirectly involved in my work for their cooperation and precious help to
complete my training successfully.
CCOOMMPPAANNYY PPRROOFFIILLEE
Bhushan Steel Ltd. has recently successfully implemented SAP system at its Sahibabad works along its sales outlets with the help of Siemens Information Systems ltd. (SISL) in first phase.
Bhushan Steel Limited is dedicated to conduct global business in a
professional and ethical manner. Bhushan Steel promotes a positive work
relationship where our Board of Directors, Executive Team and employees
are encouraged to take personal responsibility for furthering these values
through adherence to our conventional principles. Explicitly expressed, our
Board, management and employees are expected to do the right thing
every day as we serve our customers and business collaborators.
The perpetual input of our employees is a powerful and invaluable tool used to ensure ceaseless maintenance of our culture of ethical behaviour. If any employee, officer or director of the company gets aware of a violation of the Code, they are not only encouraged, but obligated, to report it. We have worked hard to create an environment where an individual who becomes aware of a Code violation can feel comfortable reporting this incident to their supervisor, or any other manager or Personnel department with whom they feel comfortable.
Principle of Bhushan:-
“Our mission is to grow our company by providing innovative strong and
highperformance products and solutions to meet our global customer needs.” Bhushan Steel Ltd formerly known as Bhushan Steel & Strips Ltd. is a globally
renowned one of the leading prominent player in Steel Industry. Backed by more than two decades, of experience in Steel making, Bhushan Steel is now India’s 3rd largest Secondary Steel Producer Company with an existing steel production capacity of 2 million tons per annum’s (approx.).
It was the vision of the founder; Brij Bhushan Singal, that the first stake was driven into the soil of Sahibabad (Uttar Pradesh) in 1987. His vision helped BSL overcome several periods of adversity and strive to improve against all odds. The company has three manufacturing units in the state of Uttar Pradesh (Sahibabad Unit),Maharashtra (Khopoli unit), and Orissa Plant (Meramandali unit) in India and sales network is across many countries.
The company is a source for vivid variety of products such as , Galume Sheets and Coils, Hardened & Tempered Steel Strips , Billets, Sponge Cold Rolled Closed Annealed, Galvanized Coil and Sheet, High Tensile Steel Strapping, Colour Coated Coils Iron, Precision Tubes and Wire Rod.
As one of the prime movers of the technological revolutions in Indian Cold Rolled Steel Industry, BSL has emerged as the country’s largest and the only Cold Rolled Steel Plant with an independent line for manufacturing Cold Rolled Coil and Sheet up to a width of 1700mm, as well as Galvanized Coil and Sheet up to a width of 1350 mm.
Vision of company:-
“The vision of evolving into a totally Integrated Steel Producer by committing to
achieve the highest standards of Quality through Cutting-Edge Technology.”
The key to Vision is to use rigorous conceptual framework and to understand how that
framework connects to the underlying DNA of enduring great companies.
A well-conceived vision consists of two major components—“CORE IDEOLOGY” and
an “ENVISIONED FUTURE”. A good vision builds on the interplay between these two
complementary Yin-and-Yang forces; it defines “What we stand for and Why we exist”
that does not change the Core Ideology and sets forth “What we aspire to become, to
achieve, to create” that will require significant change and progress to attain
the Envisioned Future.
Our Vision
About Culture: -“To make it a place where all the people can thrive living,
learning and working in a clean, safe and healthy environment.”
About Values:-To corporate values as “the rules or guidelines by which a
corporation exhorts its members to behave consistently with its order, security
and growth.”
About People: - “See the good in people and try to develop those qualities” i.e.
preparation and grooming of the next generation of the young thinkers.
About Customers: - “Sell good merchandise at reasonable price; treat our
customer like we would treat our friends and the business will take care of itself.
Bhushan Steel’s endeavour is to attain the highest level of Customer
Satisfaction.”
About Products: - “We should always be the pioneers with our products – out
front leading the market.”
Policies:-
INTEGRATED QUALITY, ENVIRONMENT, OCCUPATIONAL HEALTH & SAFETY
MANAGEMENT SYSTEM POLICY
Bhushan Steel Ltd. commits to produce cold rolled and galvanized steel sheets of world
class quality in a safe, healthy and clean environment by involving employees with
continual improvements in system implementation, technological advancement,
operational integration, prevention of pollution & hazards maintaining
Legal compliance and satisfying needs & expectations of Customers:-
For Environmental Management System we have ISO 14001:2004 Certification
For Quality System we have ISO/TS 16949:2002 Certification
For Safety Management System we have OHSAS 18001:2007 Certification
Current Capacities:-
Milestone:-
Most brilliant milestone in BSL’s journey of excellence is setting up of Steel and Power
Plant in Orissa.On completion, the Plant will be one of the largest integrated Hot
Rolled Steel and Power complexes of the nation.
BSL has emerged as the country’s largest and the only CR Steel Plant with an
independent line for manufacturing Cold Rolled Coils and Sheets up to a width of
1700mm, as well as Galvanized Steel Coils and Sheets up to width of 1350mm.
Bhushan Steel has transformed to 3rd largest producer of Cold Rolled Steel with an
installed capacity of one million tons and sales of more than USD 1 Billion.
Finished Product List of Sahibabad Plant:-
1. Cold Rolled Coil
2. Cold Rolled Sheet
3. Galvanised Plane Coil
4. Galvanised Plane Sheet
5. Galvanised Corrugated Sheet
PROCESS ROUTE OF CRCA MATERIAL:-
Pickling line:-
Mainly pickling of coil is used to remove corrosion or rust, which is produced on coil surface due to interaction of coil surface with air and moisture. This may form an oxide layer on coil Surface, which may cause of reduction of metal and improper surface finish. Pickling in a solution of hydrochloric or sulphuric acid. The acid dissolute the oxide scale from the strip surface according to the reaction: Fe2O3 + 6HCl = 2FeCl3 + 3H2O .
Rinsing and passivation of the strip. At this stage the acid residuals are washed by water from
the strip. Passivation film is formed on the strip surface providing corrosion protection.
Drying.
Edge Trimming.
Oiling.
Recoiling.
Specification:
Type of Line Push - Pull. Material Hot Rolled M.S.
Strip Thickness 6.0 mm. Strip Width 1700 mm.
Coil O.D. 2000 mm.
Coil Wt. 30 MT.
Pickling Cascade with 2 / 3/ 4 Tanks. Rinse Multi Stage Cascade Hot Rinse.
Pickling Medium HCL.
Additional Features:- Online Side Trimming.
Oiling. Roll Bending.
Quick Work Roll Change.
These pickling lines can process strips varying from 1.0mm to 12.0mm thick and 200mm to 2000mm
wide. Picking lines process one coil at a time, therefore eliminating the need for joining strips. This
process allows immense flexibility of operation & also ensures easy operation and maintenance. As
accumulators are not required in these lines, thus making them cost effective in nature. These
pickling lines are capable of producing between 200,000 to 1,000,000 Tons per annum.
Hot Rolled Slitter :- This process is performed for removing unwanted material, giving fatness, side cutting to get desired shape or width , remove side bending, defects like notches etc.
Various process involved are- • Loading of coil
• Feeding of coil • Setting of cutter
• Trimming • Recoiling
• Removal of coil • Stepping & labeling of output material
• Storage of output material
Slitting Lines Slitting Lines, Slitting Lines have been successfully put into operation in well-known production plants & service centres. These lines have the capability to meet client's demand for minimum burr, no damage to the
surface, high production capacity etc., to the fullest. The high automation level of the lines reduces the need for operator attendance and ensures economy of operation.
Characteristic Features:
• High automation level to achieve high economic efficiency • Minimum burr on strip edges due to high running accuracy of knife arbors
• No manual interferences required as the edge scrap baller is pit mounted
Additional Features : o Quick Slitter Head Change with Standby Slitter Head. o Dual speed lines to cover wider range of thickness.
H.R.Slitter Specification :
a) Type of Line Loop / Pull Thru'. b) Material Hot Rolled M.S. c) Strip Thickness 10.0 mm. d) Strip Width 2000 mm. e) Coil O.D. 2000 mm. f) Coil Weight . 3MT. g) Line Speed 200 mpm.
Additional Features :
Quick Slitter Head Change with Standby Slitter Head.
C.R.Slitter Specification:
I. Type of Line Single / Double Loop.
II. Material CR FH / CRCA / GALVANIZED / COLOUR COATED.
III. Strip Thickness 3.0 mm.
IV. Strip Width 1650 mm.
V. Coil O.D. 2000 mm.
VI. Coil Wt. 3MT.
VII. Line Speed 250 mpm.
Additional Features:
Quick Slitter Head Change with Standby Slitter Head.
Galvanizing Lines:-
Galvanizing Lines: -We offer hot-dip galvanizing lines. The lines manufactured by us are furnace
type, heat to coat type or wet flux type. Efficient air-knives control the thickness of coating with great
precision, either through manual settings or through automatic coat control systems. The materials
can be pickled hot rolled steel, cold-rolled steel of CQ, DQ quality & full hard in nature.
Specification:
Type of Line Wet flux.
non-ox furnace.
Material C.R. full hard.
Strip Thickness 0.6 mm. (wet flux)
1.5 mm (furnace)
Strip Width 1250 mm.
Coil O.D. 1850 mm.
Coil Wt. 22 MT.
Line Speed 90 mpm. (wet flux)
150 mpm (furnace).
Coating 90 - 250 gms/m2.
Additional Features:
• On Line Skin Passing.
• On Line Tension Leveling.
• Double Recoiler on Exit Side
TECHNICAL DATA SHEET FOR PREPAINTED GALVANIZED PRODUCTS
Parameters Technical details/specifications/Stds
Product name BHUSHAN RAINBOW
Reference standard ASTM 755
0ther containing standards JIS G3312, IS 14236, ECCA
Strip thickness mm 0.20 to 1.2 0
Strip widths mm 900 to 1250
Substrate material Zinc coating as per ASTM A 653/A 653M with steel base as per
ASTM std
Substrate Coating mass gm/m2 Substrate coating mass class
80 to 275
Z120; Z150; Z180 and Z275 as per ASTM std
Or As mutually agreed
Grade designation
Gr 50/ Gr 80/CS type A, B as per ASTM std
Yield strength Mpa min Tensile strength Mpa min
340 for Gr 50 & 550 fo r Gr 80
410 for Gr 50 & 570 for Gr 80
Paint type Regular Polyester/Silicon Polyester/PVDF
Paint coating thickness (DFT) Top coat 18 to 22 microns (+5 microns primer)
Back coat 5 to 8 (including primer)
Digital DFT meter accuracy Accuracy +/- 2% of reading) as per ASTM A 153
Pencil hardness H or Harder
Gloss 15-80% at 60 degrees ASTM D 523
Resistance to chalking QUV ASTM D 53
1000 HRS –rat ing ≤4 for PVDF,
750 HRS –rating ≤4 for others
Resistance to corrosion (ASTM B 117)
500 HRS with blister density ≤2, creepage ≤2 mm.
Resistance to Humidity 1000 HRS blister density ≤ 2 (ASTM D 2247)
Resistance to color change QUV- ASTM
G 53 2000 HRS (delta E ≤ 5 unit) for PVDF
1000 HRS (delta E ≤ 5 unit) for others
Flexibility 4 T- (ECCA) - no cracking
Resistance to abrasion ≤20 mg as per 100 cycles
Resistance to Acid/solvents No discoloration/no blistering- ASTM D 1308
Product certification All products are accompanied with MTC and packing list.
Quality System ISO 9001 – 2000
Galvanized Plain CoilTechnical details/specifications
PLAIN SKIN
PASSED CORRUGATED
HILGP
PETROL/FUEL
TANK
FGP
FAN
BLADE
GPC
BUSES/COACHES
Thickness
(mm)
0.10 to
2.50
0.30 to
2.50 0.12 to 1.60 0.30 to 2.50
0.40 to
1.20 0.60 to 1.60
Width
(mm) upto 1350 upto 1350
602,762,800,
900,1050 200 to 1350
100 to
1350 100 to 1350
Surface
Finish Regular &
mim.spangle
Matte with
zero/min.
spangle
Regular
Spangle
Matte, Bright
Finish, No
spangle
Matte
finish,
No
spangle
Matte, Bright finish,
No spangle
Coating
Mass
(gms/m2)
80 to 300 80 to 300 80 to 300 20 to 80 60 to
90 60 to 80
Grades Soft/Lock
forming EDD,
DD,D,
SPCEN,
SPCD,SPCC
Roofing
EDD, DD,D,
SPCEN,
SPCD,SPCC
SPCD,
SPCC
SPCEN, SPCD,
SPCC
Galvanized Plain sheet Technical details/specifications
PLAIN SKIN PASSED CORRUGATED
HILGP
PETROL/FUEL
TANK
FGP FAN
BLADE GPC BUSES/COACHES
Thickness
(mm) 0.10 to 2.50 0.30 to 2.50 0.12 to 1.60 0.30 to 2.50
0.40 to
1.20 0.60 to 1.60
Width (mm) upto 1350 upto 1350 602,762,800,
900,1050 200 to 1350
100 to
1350 100 to 1350
Cut to
Length (mm) upto 4500 upto 4500 upto 4500 upto 4500
upto
4500 upto 4500
Surface
Finish Regular &
min.spangle
Matte with
zero/min.
spangle
Regular Spangle
Matte, Bright
Finish, No
spangle
Matte
finish, No
spangle
Matte, Bright finish, No
spangle
Coating
Mass
(gms/m2)
80 to 300 80 to 300 80 to 300 20 to 80 60 to 90 60 to 80
Grades Soft/Lock EDD, DD,D, Roofing EDD, DD,D, SPCD, SPCEN, SPCD, SPCC
GP 2
PROCESS MACHINE/EQUIPMENT
Loading of coil coil car &uncoiler
Welding Welding unit
Degreasing-1 spray tank
Brushing brushing unit with motor
Degreasing -2 spray tank
Hot rinsing spray tank
Dryer two blowers
Pickling spray tank
Rinsing spray tank
MATERIAL SPECIFICATION Low carbon cold rolled full hard steel strips
Thickness 0.08mm to 0.5 mm
Width 1005 mm (max.)
Weight 6 MT (max.)
LINE SPECIFICATION
Speed
Entry speed 20 M/min(min.) 95 M/min(max.)
Tension of the strip
Entry end 60 kg(min.) 166 kg(max.)
Entry accumulator 90kg/cm2 (max.)
WELDING LINE SPECIFICATION Welding unit type DH 100/3 ML-125
Input voltage 415V +5%
Frequency 50 Hz
KVA 50 % DC Min.100 amp Max. 200 amp
Throat depth 125 cm(Max.)
Stroke 5cm
Air pressure 6kg/cm2
Transformer cooling water cooling
Flow rate of water 15 litre (Minimum)
WORK INSTRUCTION FOR GP -2 CENTRE SECTION PROCESS MACHINES/EQUIPENTS
Preheating Electric Heater
Fluxing Steel Box
forming SPCEN,
SPCD,SPCC
SPCEN,
SPCD,SPCC
SPCC
Galvanizing Zn tank (having 25 MT Zn , 95 MT Pb) temp. 723 -738 K
Air cooling Air Blower
Water quenching Quenching tank
LINE SPECIFICATION
Speed
Process section 20 M/min (Min.) 78 M/min (Max.)
Threading speed 15M/min
FLUXING Ph is kept in the range of 2-3. The properly cleaned strip passes through flux bath in zinc pot having temperature 723 – 738 K Composition of flux bath should be
Zinc chloride 35-60 %
Ammonium Chloride 1-6%
Sodium chloride 4.5- 8 %
Any other content less than 1 ppm.
Fe content should not be more than 0.01 gram/litre
GALVANIZING SECTION Composition of Zn bath
Zinc 96 – 99%
Aluminium 0.10 – 0.30%
Lead 0.5 1.5%
Tin As per requirement
Antimony As per requirement
Air Cooling Galvanized strip passed through the jet of air.
WATER QUENCHING Strip is quenched by treated water in quenching tank at temperature of maximum 343K & water is discarded if hardness exceeds 80 ppm.
Whole surface of strip should be dipped in quenching tank filled with 50 – 75 % of treated
water for even quenching.
GP 2 EXIT SECTION
PROCESS MACHINE/EQUIPMENT
Passivation Dipping Tank
Dryer L-84
Printing Printing Machine Recoiling Recoiler & coil car.
PASSIVATION The quenched galvanized strip passes through a passing tank containing passivation salt (Conc. 1 – 2.5 %) at
temperature of 40 -80%.
PRINTING
Dried galvanized strip then passes through printing assembly & the required “WORD/FIGURE” is
printed on the galvanized strip.
RECOILER Printed galvanized strip is wound on recoiling mandrel.
DEFECTS
Dent
Roll Mark & Scratches.
Passivation Spot.
Flux Carryover /Black Spot/Flux Spot.
Over coating
White Rust.
If Ph value > 3 then let it should be drain out. DRYER Passivized strip is then dried with hot air blast. Hot air removes all moisture from its surface. Temperature of hot air is kept in the range of 393 – 453K.
PRESSURE/TENSION ON STRIP
Recoiler Tension 100 Kg (Min.) 1010 Kg (Max.)
Exit accumulator pressure 90 Kg/cm2 (Max.)
ROLL GRINDING MACHINE It is a three rolled grinding machine. It is basically used to treat the rolls which are used continuously in certain machines like Hitachi Mill, Pickling line etc. In this machine we use two categories of rolls namely Intermediate Rolls Back up roll
PROCESS FLOW DIAGRAM FOR RGM Pre inspection of roll: - In this step the rolls are inspected in order to identify their defects.
Loading of roll: -In this step the rolls which are found defected ones are load with the help of coil car. Selection of Machine Control Program (MCP): In this step particular computer operated programs are selected to operate on the loaded roll. Rough Cutting of Roll: -In this step rough cutting of rolls are done with the help of shear.
A shear cutting oil is used in order to control friction and to reduce the temperature develop on the surface. Inspection of roll: - This step is performed to find the any defects or extra material attached to the surface of
the rolls. If any defect is found then the roll is sent for the cutting operation to remove those defects .Finishing of rolls: - After the inspection process finishing operation is done on the roll. Now the rolls are ready
to use for their operation in the machines like Hitachi Mills, SPM etc. Texturing (only for W/R): In this process Electric discharge is used in order to provide the desired Roughness to
the rolls so that they perform their function satisfactorily.
If this operation is not conducted then roll will not perform its work properly and hence the product formed will not be of good accuracy and precision.
Unloading, storage & Transport: Finally the defect free roll is obtained .Now it is ready for reuse. Now it is unloaded with the help of coil car and sent back to the different mills for use.
DEFECTS OF ROLLS Roll Bite Pinchers
Chattering Marks Floppers (Pinching Marks)
GP1
A. WORK INSTRUCTION FOR ENTRY SECTION
APPROVED PROCESS APPROVED MACHINERY Coil loading Coil car & uncoiler Welding Welding unit
B. LINE SPECIFICATION MONITORING OF PROCESS PARAMETERS
SPEED Entry speed 15 – 20mpm
TENSION Entry (POR) 56 –560mpm
Entry accumulator 105 TO 1050 Kg
POSITION Entry accumulator1 – 90% Filled POR initial data 500mm – 600mm
C. OLD ROLED MATERIAL SPECIFICATION
Hardness of material 45 – 100 HRB
Thickness of strip0.17 – 2.2mm
Width500 – 1280 mm
Weight0.5MT (min.), 22MT (max.)
Initial diameter of coil 500 mm – 600mm D. COLD ROLLED MATERIAL INSPECTION
Preferably coil should be free from edge cut & saw edges.
Shape & surface finish of the cold rolled coil is inspected by entry operator & also enters the
same in log book.
E. INTRODUCTION FOR ENTRY SETUP Made entry section ready by pressing switch.
Make accumulator tension on by pressing switch.
Make POR tension on by pressing switch.
Make entry start by pressing switches.
F. COIL LOADING
Coil is loaded with the help of coil car.
Electrolytic Cleaning Line
Utilizing a performance enhanced, low-temperature, high
volume, updraft re-circulating hot air design, the Electrolytic
cleaning line is ideal for refreshing steel products and other
metallic mater. The Electrolytic cleaning lines are the ideal
wet cleaning complement for advanced Electrolytic
components.
Specification :
Type of Line Electrolytic Cleaning with Alkali
Material Cold Rolled M.S.
Strip Thickness 2.5 MM.
Strip Width 1650 MM.
Coil O.D. 2000 MM
Coil Wt. 30 T.
Line Speed 200 MPM.
Additional Features : On line Trimming
Electrolytic Cleaning is required in case material rolled with high percentage of oil while
reduction in mills goes for annealing in furnace. Oil free base material is essential for the
production of bright and corrosion resistant steel. Sodium Orthosilicate is used as cleaning
agent in ECL. Tension is given according to thickness, width based on customer
requirement.
The installed production capacity of the line is 86102 MT/Annum.
ROLL GRINDING MACHINE:- It is a three rolled grinding machine. It is basically used to treat the roll which are used continuously in certain machines like Hitachi Mill , Pickling line etc. In this machine we use two categories of rolls namely
Intermediate Rolls
Back Up Roll
PROCESS FLOW DIAGRAM FOR RGM
1 Pre inspection of roll:
In this step the rolls are inspected in order to identify their defects.
2 Loading of roll: In this step the rolls which are found defected ones are load with the help of coil car.
3 Selection of Machine Control Program (MCP):
In this step particular computer operated programs are selected to operate on the loaded
roll.
4 Rough Cutting of Roll: In this step rough cutting of rolls are done with the help of shear.
A shear cutting oil is used in order to control friction and to reduce the temperature develop on the surface.
5 Inspection of roll:
This step is performed to find the any defects or extra material attached to the surface of the rolls.
If any defect is found then the roll is sent for the cutting operation to remove those defects.
6 Finishing of rolls:
After the inspection process finishing operation is done on the roll.
Now the rolls are ready to use for their operation in the machines like Hitachi Mills, SPM etc.
7 Texturing (only for W/R) :
In this process Electric discharge is used in order to provide the desired Roughness to
the rolls so that they perform their function satisfactorily .If this operation is not conducted then roll will not perform its work properly and
hence the product formed will not be of good accuracy and precision.
8 Unloading, storage & Transport:
Finally the defect free roll is obtained .Now it is ready for reuse. Now it is unloaded with the help of coil car and sent back to the different mills for use.
DEFECTS OF ROLLS Roll Bite
Pinchers Chattering Marks
Floppers (Pinching Marks)
Annealing Line
Annealing Line: - The demand for better annealed stainless steel has increased. Annealing is a heat-
treating process conducted under controlled-atmosphere furnace to minimize oxidation, so that the
product surface remains clean. It is very common for continuous annealing of strip products and stainless
steels.
Type of Line Horizontal Tight Line.
Material Stainless Steel.
Strip Thickness 1.5 MM.
Strip Width 660 MM.
Coil O.D. 1650 MM.
Coil Wt. 10 T.
Line Speed 30 MPM.
AdditionalFeatures: Tension control in closed loop.
Annealing For Stainless Steel:-
The heat treatment has to be specific in annealing and
pickling line to find the best compromise between strength and ductility without neglecting the surface finish.
Annealing and pickling lines (APL's) are used for the treatment of hot rolled (HR) and cold rolled (CR) stainless steel strips.
HR Austenitic & CR strip is annealed and pickled
continuously in an APL and HR ferric strip is only pickled. Lines for HR & CR, as well as dedicated APL's process the majority of the stainless steel production.
Annealing at a temperature 1100-1300ºF (600-700ºC) in a controlled reducing atmosphere (commonly a mixture of Hydrogen and Nitrogen) preventing oxidation of the steel surface. Annealing results in recrystallization of the steel Grain structure and in stress relief. There are two alternatives of annealing process continuous annealing line and batch annealing furnace. In the continuous annealing line (see the picture below) steel strip passes annealing furnace at a controlled speed. In the batch process steel strip coils are stacked on top of each other in the bell type furnace. Batch annealing allows
to achieve lower hardness and higher ductility of the steel than in alternative continuous annealing.
BATCH ANNEALING FURNACE
The process of annealing of cold rolled coil is carried out to obtain the desired properties in the
finished coils. For this, the material is heated to predetermined temperature in a protective atmosphere and soaked for a specified time before it is put to room temperature. Optimum condition with annealing atmosphere, annealing cycle, sealing and purging have to be maintained to obtain a finished product with bright surface, desired micro structure and uniform properties throughout the coil.
HSD is used for heating the surface. Nitrogen is purged inside the inner cover. Nitrogen is obtained from PSA Unit. The installed production capacity of the line is 75881 MT/annum.
Finishing/Slitting Lines
Slitting Lines: -Slitting Lines have been successfully put into operation in well-known production plants &
service centres. These lines have the capability to meet client's demand for minimum burr, no damage to the surface, high production capacity etc., to the fullest. The high automation level of the lines reduces the need for operator attendance and ensures economy of operation.
Characteristic Features:
High automation level to achieve high economic efficiency Minimum burr on strip edges due to high running accuracy of knife arbors No manual interferences required as the edge scrap baller is pit mounted
Additional Features :
Quick Slitter Head Change with Standby Slitter Head. Dual speed lines to cover wider range of thickness.
H.R.Slitter
Specification :
Type of Line Loop / Pull Thru'.
Material Hot Rolled M.S.
Strip Thickness 10.0mm.
Strip Width 2000 mm.
Coil O.D. 2000 mm.
Coil Wt. 30 MT.
Line Speed 200 mpm.
Additional Features :
Qquick Slitter Head Change with Standby Slitter Head.
C.R.Slitter:-
Specification:
Type of Line Single / Double Loop.
Material CR FH / CRCA / GALVANIZED / COLOUR COATED.
Strip Thickness 3.0 mm.
Strip Width 1650 mm.
Coil O.D. 2000 mm.
Coil Wt. 30 MT.
Line Speed 250 mpm.
Additional Features :
Quick Slitter Head Change with Standby Slitter Head.
Rewind cum Trimming Line Built from the basic elements of the compact trimming line, the modular line mechanically trims the edges through chip removal process. Any desired dimension is possible depending on strip width and thickness. The number of tools operating simultaneously is variable. It is frequently used in the welded tube production.
Specification: Type of Line Tight Line With Driven Trimmer.
Material CRFH / CRCA.
Strip Thickness 2.0 mm.
Strip Width 1250 mm.
Coil O.D. 2000 mm.
Coil Wt. 25 MT.
Line Speed 500 mpm.
Additional Features: Two - speed arrangement.
Coil build-up Lines
The coil build-up lines are used for side-trimming of the strips and also provide the coils with leader strips that can be reused for optimization of the yield. With suitable inclusion of welder, these lines can
be used for building up bigger coils from small coils, with roll-able weld.
1. LOADING OF COIL
Cold Rolled (CR),GP Coil or skin passed coil is loaded on the coil car/turnstile by
crane.
2. FEEDING OF COIL
The coil is fed from uncoiler using Peeler Table.
The coils outer 2/3 damaged wraps are cut by shear.
3. SETTING OF SLITTER & SLITTING OF COIL
Proper set of cutters and rubbers to be used for setting of slitter.
During slitting the operator must check the back tension & regulate it properly.
The pneumatic pressure on pressure pad should in between 2-2.5 bar.
4. CLEANING OF MACHINE
All rotating parts & rolls should be cleaned regularly.
Line should be cleaned regularly after processing of approx. 80 – 100MT of
material.
5. RECOILING &UNLOADING.
6. PACKING OF COIL
COLD ROLLED SLITTER
MINIMUM MAXIMUM
I. Speed- 400 mpm
II. Coil width400 mm1700 mm
III. Strip thickness0.10mm3mm
IV. Coil weight - 3 MT
COLD ROLLING MILL:- There are two types of Cold Rolling Mills operates, which are 6 Hi Cold Rolling Mill and 4 Hi Cold Rolling Mill. Pickled Hot Rolled Coils of higher guages are reduced to required thinner guages by passing through the Mills. In 6 Hi Mill the reduction achieved is upto 0.13mm ultra-thingauge whereas 4 Hi can reduce the thickness upto 0.25mm. The computer controlled rolling process ensures closure thickness tolerances and perfectly flat strips. The installed production capacity of 6 Hi Mill is 23,856 MT/annum and 4 Hi Mill is 43,502 MT per annum.
Cold Rolling Mills Our cold rolling mills are specifically designed for breakdown rolling of ferrous/
non-ferrous sheet & strip. The rolls are manufactured from alloy steel, having high hardness of about
60-62 HRC. The produced steel is considered to be "full hard". Cold-rolled steel products begin as hot
rolled pickled and oiled coils. These coils are "cold-reduced" by passing them through a cold
reduction process on a reversing mill under high tension and pressure.
Mill Specification:
Type 2HI / 4HI / 6HI.
Material HR. / MS / SS / AL.
Input Thickness 6.0 MM.
Output Thickness 0.15 MM. (Output).
Width 1250 MM.
Coil O.D. 2000 MM.
Coil Wt. 25 T.
Mill Speed 500 MPM.
Additional Features:
Hydraulic Automatic Gauge Control. Thickness Gauges. Roll Bending. Quick Work Roll Change.
Skin Pass Mill:-
Skin Pass Mill These skin pass mills are specifically designed for manufacturing sheet / strip of
medium hardness or to provide finish pass. The Rolls are made of alloy steel & have high hardness,
which is generally up to 65 HRC or more. For increasing demands with respect to strip flatness,
elongation and roughness, especially for hard material grades, skin-pass mill is an ideal solution due
to higher rolling forces and torques that can be achieved in this case.
Temper rolling (skin pass rolling) - final cold rolling operation with low thickness reduction
conducted in order to impart to the steel required levels of hardness, evenness and surface finish.
Four-high rolling mill is used for tempering.
Most of annealed low carbon steel strips are tempered since they are too soft (HV<110) in annealed
condition. Bending and deep drawing operations of soft annealed steel may cause formation of kinks
(cross breaks) and stretcher strains, which are the result of localized stretching of the strip at low cold
deformation beyond the yield point. Light tempering of annealed strip (non-kinking temper, pinch
pass) produces strip surface conditions, which do not cause formation of cross breaks and stretcher
strains. Hardness of pinch passed steel is about 115 HV. Other temper conditions of steel strip are:
eighth hard (105<HV<125), quarter hard (115<HV<130), half hard (130<HV<160), three quarter hard
(150<HV<185).
SAFETY
The service provider and his men should comply with personal protection equipment(PPE)requirement decided by the organization safety department like Cut Resistance , Hand Gloves, Safety Helmets and safety Helmets and Safety Shoes.
All the PPE’Smust be worn while working on job. The service provider should be competent enough to supervise his men.
GENERAL SAFETY GUIDELINES
Service Provider must not operate any equipment in manual mode without permission
from authorized engineer.
Service Provider must not go to any equipment while moving.
No person is allowed to stand on coil car / slitting line.
No By-passing of interlocks and no pre assumptions for any equipment operation.
Use Proper PPE’S& Safety platform while packing.
Ensure that, fingers should be away from strapping procedure and while working with tensioner.
Service Provider trained operator should handle consumables for packing of Coils.
Operators should be away from under crane, while crane carrying the Coil/ Plates to packing saddle/ packing area.
Service Provider must remove the waste consumables immediately, disposal to Specified scrap bin and keep the area neat &clean.
Service Provider must keep only good quality wooden logs for packing. Service Provider must always wear sufficient PPE’s inside the plants.
Service Provider must keep safe distance to the coils & packs while packing.
Service Provider must not modify any tools or equipment’s. Service Provider must not touch any movable parts.
Service Provider must riggers must be alert while pack stacking procedure in yard.
Extra care to taken while packing with fork lifter. The signal to be given to fork lifter
driver by standing at least one meter away from pack.
Service Provider must keep the packs stack height maximum 6 feet and must not
stackthe packs more than 6 feet height.
Rigger must ensure as coil properly gripped in sling-gofer/c-hook than after give the
signal to the crane operator.
Service Provider must not put wooden blocks for packing while the crane is moving with load.
Quality control: We have fully fledged laboratory with test equipment’s such as Emission
spectroscope for the chemical analysis, computerized Universal testing machine with stress-strain graph for tension tests, surface finish tester, Hardness testers using both Vickers and Rockwell scales, LFQ testing machine, Cupping tester, on line Radiometric and off line chemical lab for coating mass, salt spray tester for
corrosion resistance, and Humidity chamber.
For Environmental Management System we have ISO 14001:2004 Certification
For Quality System we have ISO/TS 16949:2002 Certification
For Safety Management System we have OHSAS 18001:2007 Certification
The main concern of the company is to maintaintheinternational norms ofsteel industry to develop the accurate and precise products by preserving the environmental balance and constituting an ecofriendly environment by
utilizing modern and advanced techniques available in the market.
R & D department :
For continuous bench marking of our product quality, we keep carrying out testing from outside laboratories. This has resulted in continuous upgrading of the process parameters confirming to any international standards. Further, we have online backup SGS inspection for all test parameters up to the point of dispatch. We are IS0 900l certified. Our products are accompanied with mill test certificates and packing lists.
Following tests are conducted in order to maintain the accuracy and
precision and standardisation of the products manufactured in the plants according to international norms of the steel market.
HARDNESS TEST: -
Hardness is a surface property.
It is defined as “the resistance of a material against permanentdeformation of the surface in the form of scratch, cutting, indentation, or mechanical wear”.
BRINELL HARDNESS TEST:-
This test is conducted for the specimen with range 0 to 10.
In this test hardened steel ball is used as an Indentor. Indentor is used to
introduce indentation on the surface.
This machine is called “push-pull button type machine” because the indenting load is applied by pushing a button.
Before conducting the test, the surface of specimen is made free from oil, grease, dust and dirt.
FORMULA:- BHN =Indenting load in (kgf)/spherical surface area of indentation in (mm2) VICKERS HARDNESS TEST
This test is similar to Brinell’s test but uses a different type of Indentor.
A Square based Pyramid Indentor of cone angle (=136 degree Celsius) between opposite faces of pyramid is used.
The applied loads may be 5, 10, 30, 50, 50, 100 or 120 kgf.
FORMULA:- VICKERS HARDNESS = 1.8544P/d2 (for cone angle = 136)
This test is performed for smaller cross sections, very hard materials, polished and nitride surfaces, and very thin test pieces.
TENSILE TEST This test is performed on machines such as given below. 1 Hounsfield Tensometer,
1 Universal Testing Machine(UTM) 2 Instron or other Material Testing Machine (MTS).
Universal Testing Machine (UTM)
The UTM have large load capacity, generally ranging from 0-4 Tonne. Materials with large sections and high tensile strength such as steel bars are tested on them.
Tensometer is generally mechanically operated while UTM’s are hydraulically operated. They can be controlled by computers or can be operated manually.
Conclusion:- Process Flow Diagram of CRM Complex
HRBlack
Cold
Continuous Pickling & Parting
Cold Rolling Process
Rewinding Annealing of Cold
Skin Pass of Cold
Cold Rolling Mill Complex (CRM)
The various processing units involved in the CRM complex and their functions are given below :
The waste liquor from pickling line, recoiling line are treated in effluent treatment plant ensuring pollution free environment. The acid regeneration plant ensures regeneration of hydrochloric acid
from waste pickled liquor for reuse in pickling line.
Continuous Pickling Line (Cpl) :
The HR Coil, which is the basic raw material, is passed through CPL to remove the oxides or scales from
strip surface to enable further reduction of thickness to desired level in Cold Rolling Mills. This processing is required since rust is formed on the surface of the coils at room temperature whereas
scales are formed at high temperature during rolling in Hot Strip Mill.
Cold Rolling Mill
Pickled Hot Rolled Coils of higher guages are reduced to required thinner guages by passing through the Mills. In 6 Hi Mill the reduction achieved is upto 0.13mm ultra-thin guages whereas 4 Hi can reduce the thickness upto 0.25mm. The computer controlled rolling process ensures closure thickness tolerances and perfectly flat strips.
Electrolytic Cleaning Line
Electrolytic Cleaning is required in case material rolled with high percentage of oil while reduction in mills goes for annealing in furnace. Oil free base material is essential for the production of bright and
corrosion resistant steel. Sodium Orthosilicate is used as cleaning agent in ECL. Tension is given according to thickness, width based on customer requirement.
Annealing Furnace
The process of annealing of cold rolled coil is carried out to obtain the desired properties in the finished coils. For this, the material is heated to predetermined temperature in a protective atmosphere and soaked for a specified time before it is put to room temperature. Optimum condition with annealing atmosphere, annealing cycle, sealing and purging have to be maintained to obtain a finished product
with bright surface, desired micro structure and uniform properties throughout the coil. HSD (High Speed Diesel) is used for heating the surface. Nitrogen is purged inside the inner cover.
Skin Pass Mill
In this process the cold rolled annealed strips are given a desired surface finish. It improves the flatness and suppresses the yield point elongation. Anti-rust oil is used on strip surface as protection from
rust.