Mdmw-iron28

Steelmaking : Fundamentals and Practice

- D Satish Kumar Research and Development

What is Steel is an alloy of Ir on and Car bon containing less than 2% carbon. Commonly used automotive and construction steels contain 0.05 – 0.5 % C Modern steels often contain additional elements for improved properties

Topics • Introduction to Steelmaking • History of Steelmaking • Pretreatment of Hot metal • Primary and Secondary Steelmaking • Continuous Casting • Steelmaking at JSW • Challenges at BOF-CCP

Classification of Steels Type of Steel

Percentage of Carbon

Mild Steel

Upto 0.25%

Medium carbon

0.25 – 0.45

High Carbon

0.45 – 1.50

Adding metals such as Ni, Cr, V, Ti, Nb etc produces wide range of alloy steels. 2.4 2.0

0.4

0.1 % C – Structures

Car Bod y C– 0.00

0.2 % C – Heavy vessel plates

5%

–C

0.5 % C – Rails

%C

0.8

0.05

0.9 % C – Cutting blades 0.6 % C – Rail wheels

%C

1.2

ans

1.0 % C – Axe

0.08

Carbon %

1.6

–C hain s

1.4 % C – Scissors / Knives 1.2 % C – Drilling items

0.0 0

2

4

6

8

10

12

14

16

JSW Steel Products

Flat Products

Why Steel Making ? Hot Metal Chemistry

Final Steel Chemistry

C

4.5

0.03

Si

0.8

0.2

S

0.045

0.005

P

0.14

0.005

Mn

0.06

0.5

Blast Furnace

Al Corex

0.025 Ni. Cr, Nb, V, Ti,

JSW grades based on End Use • • • • • • • •

JVCR** JVLP** JVGL** JVCM** JVDR** JVSL** JVWT** JVTR**

• • • • • •

JVST** JVCH** JVWR** JVHT** JVLN** JVBQ**

Cold Rolling & Annealing Simple Pressure Vessels Cold Rolling & Galvanizing Cold Rolling (Medium Carbon) Drawing & Pressing Quality Sheets Electrical stamping Steel Welded Tubes And Pipes Transport Industry & Special structural Quality Plates & Sheets Structural Quality Plates for Engg & Auto Chequered plates for structural purpose Atmospheric Corrosion Resistance High tensile for structural & auto Line Pipe For Boiler applications

Some common grades and composition Element s

Cold Rolling

Structural

Transport

Line pipe

C Mn

0.04 0.2

0.15 0.9

0.08 0.9

0.1 1.1

S

0.015

0.02

0.015

0.011

P Si Al Nb Ti V YS UTS

0.015 0.02 0.035

0.02 0.1 0.04

200 Mpa 310 Mpa

0.02 0.015 0.08 0.2 0.04 0.04 0.04 0.05 0.03 0.04 0.07 0.06 280 Mpa 510 Mpa 560 Mpa 450 Mpa 580 Mpa 630 Mpa

Applications

Steel constitutes 60% of the weight of the automobile

• Bumper beam front and rear • Bumper beam inner and outer • Reinforcement waist B-pillar inner

• B-pillar inner, • Extension C-member kick-up • Crossmember support for the front seat.

FIRST DUAL PHASE STEELS Parts: B-Pillars, Rocker

Material with YS 500 MPa are recommended for most of the passenger cell Hydroformed front rails and the hydroformed body side members also use this material

Parts: Inner and outer closeout between the crash box and the dash

83% of body structure: ULSAB 63% of body structure: ULSAB-AVC

Alloying Elements Primary alloying elements Secondary alloying elements

C, Mn, Si Ni, Cr, Mo, V,

Nb, Al Residual / Tramp elements Pb, Zn

S, P, Cu, Sn,

Steelmaking Route Iron Making

Pretreatment

Primary Steelmaking

Secondary Steelmaking

Continuous Casting

Rolling