09/25/14
Overview of technological breakthrough & in-house innovations in JSW Steel Ltd, Dolvi works
Mrigandra Singhai, Harsha V Sharma, Pradip K Patra, Alok Chandra

09/25/14

Overview of JSW Steel Dolvi Ltd.

Breakthroughs in Iron making area

Breakthroughs in CONARC furnace

Breakthroughs in CSP caster

Breakthrough in products

3
Overview of JSW Steel Dolvi Ltd.
3

JSW Steel Ltd, Dolvi Works
4
4

DOC- 1994
DOC- 1994
JETTY 10 MTPA
DOC- 2000
DOC- 2005
SIP - 1 .6 MTPA
DOC- 1998 Ph1, 2005 Ph2
BF - 2.0 MTPA
DOC- 1998 Ph1, 2003 Ph2
SINTER - 2.8 MTPA
DOC- 2013
Dec’ 2010 Setup
EAF – 4.5 MTPA CSP - 3.3 MTPA

Feb-2014
Coke Oven – 1
MTPA
DOC- 1994
A Journey Begins at Dolvi
DOC- 1994
Feb-2014
JETTY 10 MTPA
DOC- 2000
Pellet – 4 MTPA
DOC- 2005
SIP - 1 .6 MTPA
DOC- 1998 Ph1, 2005 Ph2
BF - 2.0 MTPA
DOC- 1998 Ph1, 2003 Ph2
SINTER - 2.8 MTPA
Mar-2013
EAF – 4.5 MTPA CSP - 3.3 MTPA
6
CPP – 55MW
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Iron Ore
Pellet Plant
4 MTPA
Process Flow at Dolvi
Iron Ore & Fluxes
Coke Oven
1 MTPA
Sinter Plant
2.8 MTPA
NG
Sponge Iron Plant
1.6 MTPA
LCP
2X300 TPD
Cal. Lime
DRI
SMS (Con-Arc)
4.0 MTPA
LCP
600 TPD
Liquid Steel
Thin Slab Caster
Two Strand
3.3 MTPA
Slab
Hot Strip Mill
3.3 MTPA
HRC
Projects Commissioned
Hot Metal
Blast Furnace
2 MTPA
Railway
Siding
Power Plant
55 MW
Existing Facilities
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7

S.N.
1
2
3
4
Plant /Facility
Captive - Jetty
Sponge Iron
Plant
Blast Furnace
Sinter Plant
Rated
Capacity
10 MTPA
1.6 MTPA
2.0 MTPA
2.80 MTPA
Year of
Commissioni ng
1994
1994
Special Features
450m long jetty with four unloading cranes
Gas based single module, being modified for usages of COG
2000 10.8m hearth dia., 2 tap holes, 5MW
GET, two SGP units, Productivity 2.6
2005 204m 2 bed area, WHR boiler, Five
ESPs, Productivity 1.61
5 Hot Strip Mill 3.3 MTPA Ph1-1998,
Ph2- 2003
Combination of CONARC & CSP, Final strip thickness 1-20mm & width 900-
1550mm
6 Lime Cal. Plant 1200 TPD 2000& 2013 Three units, 2x300 from MERZ &
7 Power Plant 53.5 MW
1X600 From Cimprogetti
Mar’2013 BF gas fired, power generation surpassed its rated capacity
8 Railway Siding 1.0 MTPA June’2013 3500 m Long Track at use for dispatch
9 Pellet Plant 4.0 MTPA of HR coils
Feb’2014 464m 2 travel grate
10 Coke Oven 1.0 MTPA Feb’2014 5.5m height, Stamp charged , 2x55 ovens & recovery type
8

JSW Steel Ltd Dolvi is the first Asian plant having CONARC for steel making & first
Indian Plant having thin slab caster ( CSP ) technology for HR coils.
9 9

`
Route 1
Sinter
BF-BOF
Iron Ore
Conventional
Routes
Coke
Route 3
CSP Route
Route 2
Pellets Coke
Iron
Ore
Flexible
Natural
Gas
Hot Strip
Mill
BF-BOF route produces
Thick Slab of 200-250 mm
Blast
Furnace
LD
(BOF)
Slab
Caster
Reheating
Furnace
Roughing
Mill
DRI
Plant
Coiling
Stand
EAF
HR Coils
Slab
Caster
Hot Strip
Mill
High
Energy
Consumpti on
High
Energy
Loss
DRI-EAF
Pellets
Iron
Ore
Natura l Gas
Coiling
Stand
HR Coils
Scrap
Reheating Roughing
Furnace Mill
DRI-EAF route produces
Thick Slab of 200-250 mm
JSW, Dolvi's Unique Steel Making Process
Scra p
Blast
Furnace
DR Plant
Twin Shell
EAF
Thin
Slab
Caste r
Ladle
Furnace
High pressure descaler
Coiling
Stand
TF
Hot
Strip
Mill
Continuous process
VOD
Plant
Energy
Efficient
HR Coils
CONARC – Thin Slab Casting casts 100% continuously Thin slab of 50-68 mm without re-heating
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10

CRM II
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Breakthroughs in Iron making area
Blast Furnace
 Existing blast furnace was brought in from
Germany where it was operational for around
7 years
 In 2000, installed capacity 1.8 MTPA with a total volume of 2581m3 and working volume
2151m3

The current furnace capacity is 2.0 MTPA.
The maximum productivity achieved is 3.07 ton/m3/day
Producti
Date on
30-03-2010
6607
01-05-2010
6190
Producti vity
3.07
2.88
Fuel
Rate Coke
500
504
289
272
Nut
Coke Coal Sinter Pellet
45
54
166
177
68
80
27
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 India’s First, NG co-injected with coal in BF
09/25/14 12
Ore
5
7

NG Injection in Blast Furnace
1.
Oxy-Coal injection was used in the year
2005
2.
In 2009 co-injection of NG along with coal injection was introduced
3.
First in the country with complete in-house design.
4.
It helped in reduction of carbon emissions as well as better control of furnace operations.
09/25/14 13

09/25/14
Advantages of NG
1.
High Calorific value . Coke replacement ratio is more than 1
2.
Ease of handling and environment friendly.
3.
Helps in smooth operation of blast furnace due to high concentration of hydrogen in tuyere gas.
4.
Reduced Sulphur input to furnace.
5.
More throughputs due to increased Oxygen input .
6.
Lower Bosh slag basicit y which helps in stable and productive operations as gangue input is reduced.
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09/25/14
Breakthroughs in CONARC furnace
Steel Making
 Asia’s First CSP Plant in combination with CONARC Process
 Offers operational flexibility of operating with 100% hot metal &
100% solid charge
 Elimination of a process step with CSP
 Lower operation cost

Lesser carbon footprints

Compact process and lower cycle times
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Triple Lance in CONARC
1.
When using 100% hot metal, CONARC is not as efficient as LD
2.
In-house development for this breakthrough modification in EAF by using multiple lances instead of one single lance
3.
The blowing strength and the penetration depth of the oxygen jet in CONARC is low as compared to LD converters
4.
CONARC has lower height to diameter ratio typically 1, whereas it is generally in the range of 1.5-1.7 for LD converters
5.
This restricts the oxygen top lance flow rate in 100% Hot Metal (HM) heats
(CONARC) to 180 Nm3/min, whereas it is in the range of 350 - 400 Nm3/min in
LD converters .
09/25/14 16

17
Analysis of the Problem
The Approach Area of Metal Bath Surface is in Direct Contact with the
Oxygen Jet will leading to higher rate of Reaction between the Metal droplets & the Slag layer, as Achieved in LD Converter.
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09/25/14
1.
By using a triple lance system in CONARC furnace, the approach area of metal bath surface is increased, leading to higher rate of reaction between the metal droplets and the slag layer.
2.
It has improved %Yield, reduced cycle time, reduced jamming of roof and elbow, and increased refractory life.
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09/25/14
Brief introduction of the organization
Breakthroughs in Iron making area
Breakthroughs in CONARC furnace
Breakthrough in products
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Highest steel in mould time:
 A high degree of caster utilization achieved by minimizing the sequence break time
 Reduced Caster breakouts, aborts
 Reduced upstream and down stream delays
09/25/14 20

 Tundish skull reduced
 Bottom design of tundish modified
 This allowed the maximum liquid steel into mould and keep the skull in tundish during tail out procedure.

 This facilitated effective metal slag separation thus improved yield.
09/25/14 21

• Reverse SEN ramping has been introduced which reduced the SEN erosion.
• SEN ramping time has been increased step by step
• Re design of New SEN according to our casting conditions
• Mixing of different grade chemistry by proper planning to reduce number of sequences.
09/25/14 22

Average casting speed is the highest among various CSP units.
09/25/14 23

 Metallurgical length extension (7.9 to 9.4m)
 Close chemistry control: A close chemistry control avoids variation in speed which may lead to breakout
 Lower Carbon values: Speed in inversely proportional to
C & S levels in steel.
 Maintaining super heat in narrow range.
 Optimization of casting powders & copper plate for high casting speed
09/25/14 24

09/25/14
Brief introduction of the organization
Breakthroughs in Iron making area
Breakthroughs in CONARC furnace
Breakthroughs in CSP caster
25

•
B- 10-20 ppm level to improve the work hardening index
• Boron has an adverse effect on hot ductility
•
Boron grades are extremely difficult to cast in CSP
Edge crack
•
Transverse corner cracks (Edge cracks)
09/25/14 26

•
Detailed statistical analysis
•
Study of hot ductility behaviour with boron addition was done using Gleeble
•
Parameters optimized :
–
Temperature: to avoiding poor ductility zone at bending
–
Mn/S ratio
–
B/N ratio to change the size & distribution of BN precipitates
Similar optimization done for Nb microalloyed steels which is highly prone to transverse corner cracks
09/25/14 27

 CSP technology was originally developed for mass production of CG/
CR grades
 Elimination of soaking pit, lower reduction ratio and shorter ROT puts limitations in producing value added grades
 Effective utilization of Nb, V & Ti has helped the company to cater the demanding needs of auto customers in all the property ranges
 Apart from lower cost due to various in built technological features, another advantage with CSP products in leaner chemistry for a given set of property requirements.
 Lower Carbon equivalent gives this steel better weld ability and leaner chemistry results in lower Ferro alloy cost.
09/25/14 28

Development of ALM650/ ALM700 grade
Ref Grade: EN 10149_2_2005 S650MC
Typical Application: A pplications includes Truck Chassis, Dumper body, Cranes and
Earth Moving Machines
Truck Chassis Earth Moving m/c
29

Chemistry
ALM650 - Specification
Mechanical Properties
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Actual Chemical & mechanical Properties
Chemistry
Mechanical Properties
31

HER
Actual Chemical & mechanical Properties
Impact Properties
Impact Energy in J (Full Size)
32

Development of coil break free EDD grade with
Nb route
 Coil break is a common problem in low C, low Mn
EDD grades
 Yield point elongation which is caused by presence of free Nitrogen in steel
 Addition of Boron/Ti and skin pass are some of the solutions
09/25/14 33

Mechanical Parameters
Non availability of free dislocations
Causes
Causes
No driving force for generation of new dislocations
Reduces
Reduces
• Increase uncoiling speed
• Increase tensile load during uncoiling
Causes
Slow speed of un-coiling
34
Causes
Inadequate
Tensile load during uncoiling

Metallurgical Parameters
Yield Point
Elongation
Causes
Causes
Free Nitrogen
Reduces
Reduces
• Add B or other nitride forming elements
• Increase CT above
640
Causes
Low Coiling
Temperature
35
Causes
Absence of Nitride forming elements

JSW Steel, Dolvi works solved this issue with Nb addition in small quantity (0.04-0.06%).
36

Ref Grade: IS 1079_2009 HR2/ HR3/HR5
Typical Application:
Drum Closure
Hand Brake Arm Different Coupler 37

 Limitation of reduction ratio in CSP
 Limitation in API grades for low temperature impact properties
 Carefully designed chemistry & high pressure compact cooling implemented
 Developed API X70 with good DWTT at - 40 o C
09/25/14 38

39

From research at IIT to implementation in mill
40
40

Development of DP590 grade
Ref Grade: IS 1079_2009 HR5_DP590
Typical Application: Wheel Rim and Wheel Disc for Automobile
41

A short ROT of thin slab caster poses a limitation on cooling path for dual phase microstructure development. To counter this, a two stage cooling process was designed to give desired cooling required for microstructure and property development.
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Phase 4: Engineering modification:
BEFORE
AFTER
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43

YS (MPa)
UTS
(MPa)
Specification ( as per EN10346:2009) 330-460 min 590
%El (in 80 mm GL) min 19
‘n’ value min 0.13
Results of initial trial
After product stabilization
385-485
340-
390*
>610
>620
24
24
>0.17
>0.17
YS/UTS ratio
0.62-0.70
0.55-0.62
44

Iron Ore
Pellet Plant
4 MTPA
5.0 MTPA
Coke Oven
1 MTPA
LCP
1200 TPD
NG
Cal. Lime
Sponge Iron Plant
1.6 MTPA
DRI
Hot Metal
Billet
Bars
2015 Setup
Billet Caster
1.5 MTPA
Bar Mill
1.5 MTPA
1 MTPA
Railway Siding
Liquid Steel
Thin Slab Caster
3.3 MTPA
Hot Strip Mill
3.3 MTPA
Slab
HRC
Iron Ore & Fluxes
Sinter Plant
2.8 MTPA
Sinter Plant
2.24 MTPA
55 MW
Power Plant

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