This document discusses the manufacturing process for producing heavy steel plates through thermo-mechanical controlled processing (TMCP). It describes the advantages of TMCP in obtaining a fine, uniform microstructure for high strength and toughness. Various applications of steel plates are outlined, along with the mechanical properties and metallurgical treatments required for plates used in boilers, pressure vessels, mining equipment, pipelines, defense, shipbuilding, construction, and wind turbines. The plate mill facilities, standard grades, testing capabilities, and marking procedures are also summarized.

1. KOMAL KUMAR
GAUTAM
IIT BOMBAY

2. MANUFACTURING PROCESS

4. METALLURGY OF PLATE ROLLING

5. Process for Producing Heavy Plates

6. The Thermo-Mechanical
Control Process (TMCP)
Through TMCP, very fine and uniform ferrite microstructure is obtained
and results in higher strength and toughness. The plate is also less susceptible
to cold cracking and has better weldability.
Concept Of Microstructure Change During TMCP

7. The Thermo-Mechanical
Control Process (TMCP)
Advantages
• Superior weldability due to lower carbon equivalent (Ceq)
• Better formability
• Excellent mechanical properties (high strength and toughness) attained
through fine microstructure
• Shorter processing time as no heat treatment is required

8. Normalising
The process of producing a stable microstructure by heating it to the high
temperature austenite and slowly cooling it.
Advantages
• Refines and ensures homogenous structure
• Reduces residual stresses from rolling
• Reduces the risk of "banding”

9. Quenching and Tempering
This is a conventional process used to harden or strengthen steel. During
quenching, the austenite is converted to martensite. The quenched alloy is
then tempered at an intermediate temperature to transform the brittle
martensite into a very fine dispersion of cementite (iron carbide) phase in
an iron ferrite matrix.

10. Quenching and Tempering
Advantages
• Increases hardness for better wear and abrasion resistance
• Improves ductility and toughness
• Reduces cracking
• Increases impact resistance

11. PLATE MILL FACILITIES
Equipments
• Rolling mills, ADCO facilities, roller tables, cooling beds, hot and cold
levellers, including automation and control systems
• Digital reheating furnace
• Heat treatment facilities covering austenising and normalising, quenching
and tempering furnaces
• Auto UT testing
• Shot blasting and painting
• Roll grinders

12. PLATE MILL FACILITIES
• Digital Reheating Furnaces
Equipped with side burners and split into different control zones for uniform heat
transfer. The digital furnaces eliminate hot spots and reduce excess scale formation on
slab.
• Rolling Mill
High roll separating force of 10,000 tonnes, almost double compared to some of the
other plate mills - generates extremely fine grain properties on plates. The mill is
supported by a fully automatic gauge controller, plan view rolling and flatness gauge to
achieve a high degree of profile, even for very thick plates.
• Thermo-Mechanical Controlled Rolling (TMCR) and Accelerated Direct
Cooling (ADCO)
Thermo mechanical rolling and DQ (direct quenching) equipped with ADCO facility for
high strength plates - can be used in demanding applications for the oil & gas sector
and other segments.

13. PLATE MILL FACILITIES
• Hot Leveller
A leveling force of 4000 tonnes, generates excellent flatness, zero distortion and an
optimally adjusted even surface. The rollers flatten plates up to 1/2 ASTM tolerance.
• Shearing Units
Equipped with different types of mechanical shears such as crop shears, double side
cut shears, slitting shears and dividing shears, the steel plates can be customized to
size and widths as specified by the customer. Mechanical cutting as opposed to
burning also leads to lesser heat treated zones and better utilization and yield.
• Heat Treatment
Heat treatment facility with austenising, normalizing, quenching and tempering to
provide desired properties of steel plates. Furnace normalization is done in an inert
atmosphere with indirect radiant type heating to ensure no scales are formed on the
surface of the plates, leading to a better yield. Quenched & Tempered facilities spray
the plates with more than 10,000 cubic metres of water in two minutes.

14. PLATE MILL FACILITIES
• Ultrasonic Testing
100% ultrasonic testing is performed for plates up to 50 mm thickness using an image
comparator and without any manual intervention. To keep it perfectly aligned the
testing unit is recalibrated every day. Testing of plates above 60mm thickness is done
manually by an international third party inspection agency.
• Marking and Traceability
All plates produced are marked with unique identification mark for traceability using
paint marking, mechanical stamping and bar coding.

15. STANDARD GRADES

17. PLATE APPLICATIONS
Type Application
Boilers and Pressure Vessels
High strength alloyed steel plates Sub-critical to super-critical boilers applications
High strength steel plates High pressure applications
Normalised steel plates Low-temperature applications
Yellow Goods & Mining Equipment
Ultra high strength steel plates with superior toughness Structures like
- Truck body
- Arm
- Support structures
High abrasion and wear resistant steel plates Shovels, quarries & mines equipment crushers, buffer
bins, buckets, dump trucks
Line Pipe
High strength and ultra tough steel plates - Line pipes carrying different fluids, gases
- Offshore structural application
Defence
High strength, hardness, toughness and anti-ballistics
steel plates
Armour tanks, mine protective vehicles
Ultra high strength and toughness, bulletproof steel Personal and vehicle protection
Special alloy steel plates Naval warships, submarines

18. PLATE APPLICATIONS
Type Application
General Engineering / Fabrication
High strength steel plates with excellent weldability General engineering / fabrication
Shipbuilding
Ultra high strength and tough steel plates - Merchant ships, cargo, bulk carriers, submarine hulls
- Low-temperature applications
Construction
Ultra high strength and tough steel plates Dams, bridges, buildings, power plant structures, penstock
Atmospheric corrosion resistant steel plates Offshore platforms, bridges, building structure
Seawater corrosion resistant steel plates Bridges, offshore platforms, structures
Wind Engineering
Higher width high strength steel plates Conical sections of long wind towers

19. PLATES FOR BOILERS
AND PRESSURE VESSELS
Applications
Boilers:
• Power plants
• Process industries
• Refineries
• Coal gasifiers
• Petrochemical exchangers
Pressure Vessels:
• Process industries
• Power plants
• Nuclear power plants
Properties Required During Service
Generally, steel plates are hot / cold formed to desired shape for major boilers to withstand high temperature,
pressure and adverse corrosive environments. Since boilers and pressure vessels carry high pressure and
temperature fluids and hold low temperature fluids, the steel plates are required to have high strength,
toughness, ductility and corrosion resistance. Due to high temperature applications, the steel plates should
have excellent creep resistant properties.

20. PLATES FOR BOILERS
AND PRESSURE VESSELS
Mechanical Properties
• High strength
• Good low-temperature toughness
• High corrosion resistance, high resistance to HIC, SSCC and embrittlement
• High creep resistance
Metallurgy
Composition / Treatment Result
Clean steel with low S and P Improved strength and toughness
Furnace normalisation Improved mechanical properties and fatigue
resistance
Vacuum Degassing Clean steel

21. PLATES FOR YELLOW
GOODS & MINING EQUIPEMENT
Applications
• Mines and quarries
• Agricultural machinery
• Vehicle manufacturing
• Cement works
• Dump trucks
• Front loaders
• Crushers
• Booms
Challenges During Usage
The plates used in yellow goods are subjected to land mines, hard rocks, loading bulk material,
shovels, crushing units, etc. The plates are therefore required to have high strength and
toughness and excellent abrasion and wear resistance.

22. PLATES FOR YELLOW
GOODS & MINING EQUIPEMENT
Mechanical Properties
• High strength
• High hardness
• High abrasion and wear resistance
• Good weldability
Metallurgy
Composition / Treatment Result
Low S, P and H High toughness
Optimum alloy chemistry with C, Mn and other
alloying elements
High strength and toughness
Alloying of special elements like Cr, Mo and Ni Improved abrasion and wear resistance
Quenching and tempering Desired mechanical properties

23. PLATES FOR LINE PIPE
Applications
• Transport of oil, gas, water
• Offshore structures
Challenges During Usage
Pipes are required to withstand very high hoop / circumferential stress generated
due to the transport elements. These are built across different geographies,
and thus would require good corrosive resistance to Sulphide Stress Corrosion
Cracking (SSCC) and Hydrogen Induced Cracking (HIC), a high Ductile to Brittle
Transition Temperature (DBTT) and a good Drop Weight Tear Test (DWTT) value.

24. PLATES FOR LINE PIPE
Mechanical Properties
• High strength
• Good low-temperature toughness
• High corrosion resistance to HIC and SSCC
• Good weldability
Metallurgy
Composition / Treatment Result
Low C and very low S and P High strength and toughness
Clean steel Improved resistance to HIC and toughness
Addition of Micro-alloying elements like Nb, Ti, V Reduced DBTT and increased DWTT
TMCR Improved strength and toughness

25. DEFENCE
Applications
• Armoured vehicles
• Mine protective vehicles
• Protective buildings
• Security vehicles
Challenges During Usage
The plates used for defence have to face battlefield conditions like land mines, rockets,
high momentum bullets and other blast materials. They are therefore required to
have excellent toughness, high strength, high hardness and good ballistic properties.

26. DEFENCE
Mechanical Properties
• High strength, up to 1,500 MPa tensile strength
• Good low-temperature toughness
• High corrosion resistance
• Good weldability
• NIJ Level-III for anti-ballistic properties
Metallurgy
Composition / Treatment Result
Proper alloy design having micro-alloys such
as Mo, Cr, Ni, B and others
Desired toughness, strength, hardness and ballistic
properties

27. PLATES FOR SHIPBUILDING
Applications
• Offshore structures
• Bulk carriers
• Tankers
• Barges
Challenges During Usage
Plates for marine applications must endure adverse load conditions like corrosion and large
cyclical loads - wave loading, sea slap and slamming thermal excursions in tropical and arctic
seas, vibration and cargo buoyancy. Thus, steel plates require high strength coupled with
good low-temperature toughness, through thickness properties, corrosion and fatigue
resistance, and tight dimensional tolerances. One of the most important requirements is
toughness in the base plate and in the HAZ regions.

28. PLATES FOR SHIPBUILDING
Mechanical Properties
• High strength
• Good low-temperature toughness
• High corrosion resistance
• Excellent high and low cycle fatigue properties
• Excellent weldability due to lower carbon equivalent and HAZ toughness
Metallurgy
Composition / Treatment Result
Clean steel, with very low S content Avoid lamellar tearing
Optimal carbon equivalent (Ceq) with low carbon and
micro-alloying elements
Good mechanical properties and good
weldability

29. PLATES FOR GENERAL
ENGINEERING / FABRICATION
Applications
• Equipment manufacturing
• Forging and industrial fabrication
• Kilns
• Gates for hydro projects
• Crane girders
• Turbine runners
Challenges During Usage
The plates are required to have high strength, toughness, corrosion resistance and good
weldability.

30. PLATES FOR GENERAL
ENGINEERING / FABRICATION
Mechanical Properties
• High strength
• High toughness
• Good weldability
• Good corrosion resistance
Metallurgy
Composition / Treatment Result
Optimum alloy design and TMCR High strength, high toughness and good corrosion resistance

31. PLATES FOR CONSTRUCTION
Applications
• Civil structures
• Bridges
• Dams
• Highways
• Power projects
• Mega residential and commercial complexes
• Telecom towers
• Hydro Project
• Offshore Project
Challenges During Usage
Plates used for this segment are pre-fabricated structures and range from low strength to
high strength depending on the application. These plates must have good corrosion resistance,
toughness, weldability and dimensional tolerances.

32. PLATES FOR CONSTRUCTION
Mechanical Properties
• High strength
• High corrosion resistance
• Good weldability
Metallurgy
Composition / Treatment Result
Optimum alloy design and TMCR High strength and toughness
Low levels of S and P Improved toughness
Furnace normalisation on demand Uniform mechanical properties

33. PLATES FOR
WIND ENGINEERING
Application
• Conical sub-sections of wind towers
Challenges During Usage
The plates used in wind engineering are subjected to high wind, tower and buckling
loads due to rotation of blades. The plates are required to have high strength and
toughness, good weldability and formability.

34. PLATES FOR
WIND ENGINEERING
Mechanical Properties
• High strength, up to 690 MPa tensile strength
• Good weldability
• Good corrosion resistance
• Weldbead bend taste on demand
Metallurgy
Composition / Treatment Result
Clean steel with low S and P Improved toughness
Optimal alloy design containing C, Mn, and High strength and toughness other micro-alloying
elements like Nb, V and Ti
TMCR / Normalised roll Desired mechanical properties

35. TESTING FACILITIES
• Optical emission spectrometer
• Universal testing machine with elevated temperature testing with a capacity of
1,200 KN
• Universal testing machine with a capacity of 2,000 KN
• Cold bend tester with a capacity of 1,000 KN
• Drop weight tear tester with a capacity of 80,000 J
• Impact tester with a capacity of 450 J
• Vicker hardness tester
• Rockwell cum Brinell hardness tester
• Metallurgical microscope with 1000 X Magnification
• NACE testing facilities
• Simulation heat treatment furnace
• Through thickness testing
• Weldbead bend test on demand

36. MARKING
• Paint marking
• Mechanical stamping
• Bar coding
R & D FACILITIES
• SME with EADX and EDSD
• Micro hardness
• Optical microscopy