05- new and future steel technologies using mn - k ichikawa nippon steel corp

8/3/2019 05- New and Future Steel Technologies Using Mn - K Ichikawa Nippon Steel Corp

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Development of Japan’s Refining

Technologies in the Past and Future

2004.6.2

By Kaoru Ichikawa Nippon Steel Corporation



2. Behavior of Mn in the Steel-making process

3. History of Process Improvement and

Influence on Manganese (1) Top-and-Bottom blowing converter

(2) Hot metal pretreatment

(3) LD-type hot metal pretreatment

(4) MURC process

4. Steel product needs (1) Automobile sheet steel

(2) Plate products

5. Future Development



China

JapanJapanU.S.A.

Germany Korea

1950 60 70 80 82 84 86 88 90 92 94 96 98 00 02 03

200

180

160

140

120

100

80

60

40

20

0

Total

1000

800

600

400

200

0

220

Japanese peak 120 million tons 1973

C r u d e s t e e

l p r o d u c t i o n

( m i l l o n t o n s / y e a r )

T o t a l p r o

d u c t i o n ( m i l l o n t o n s / y e a r )


http://slidepdf.com/reader/full/05-new-and-future-steel-technologies-using-mn-k-ichikawa-nippon-steel-corp 4/49NIPPON STEEL CORPORATION

1960 65 70 75 80 85 90 95 2000

1,000

800

600

400

200

0

500 600

5

ChahgesChahges in the consumption of in the consumption of

steel products in JAPANsteel products in JAPAN

T h e p e r

T h e p e r - - c a p i t a c o n s u m p t i o n o f s t e e l

c a p i t a c o n s u m p t i o n o f s t e e l

p r o d u c t s ( k g p e r p e r s o n )


The average consumption in the advancedThe average consumption in the advanced

industrial nations is approx. 500 to 600 kgindustrial nations is approx. 500 to 600 kg

per person.per person.



1000

100

10100 1,000 10,000 100,000

GDP US dollar per person

Korea Japan 575kg

Russia 173kg

Thailand 121kg

China

132kg

India 27kg

GermanyU.S.A.

Average

135kg

T h e p e r

T h e p e r - - c a

p i t a c o n s u

m p t i o n o f s t e e l

c a

p i t a c o n s u

m p t i o n o f s t e e l





Crude steel 2001

TotalTotal 846846 million tonmillion ton

AsiaAsia 363363 million tonmillion ton 4242

10344 152

JapanJapan KoreaKorea ChinaChina

OthersOthers

496496

The steel demand

900

700

500

300

100

362 422 449

A s ia A s ia 2 42 4

T he w or ld t o ta l increa se

d

T he w or ld t o ta l increa se

d 1313

2001 2002 2003 2001 2002 2003 2001 2002 2003 2004

73 72 7238 44 44

174 211 232 255

m i l l i o n t o n s

Japan Korea China

Consumption of steel productConsumption of steel product million tonsmillion tons

million tonsmillion tons



1997 98 99 2000 01 02 03 05

6

5

4

3

2

1

01995 96 97 98 99 2000 01 02

30

20

10

0

16

12

8

4

0

The outputs of automobilesThe outputs of automobiles The output of electric appliancesThe output of electric appliances

Automobile Automobile

BusBus Truck Truck

F o r e c a s t

F o r e c a s t

Air conditioners Air conditioners

RefrigeratorsRefrigerators

ChinaChina

JapanJapan

ChinaChinaJapanJapan

48 50

110 112 127 146 164 216 420 600

5761

70

109 m i l l i o n

m i l l i o n



1,100

1,000

900

800

700

600

500

400

300

200 C r u

d e s t e e l p r o d u c t i o n

m i l l i o n t o n s / y e a r

1960 70 80 90 2000 2010 2020

Crude steel productionCrude steel production

ForcastForcast made at the endmade at the end

of the 20th centuryof the 20th century

Forecast after China,a newForecast after China,a new

growing market, is takengrowing market, is takeninto accountinto account



2002

2010

2020

2030

2040

2050

Forecast for the world populationForecast for the world population Forecasts for the crude steel productionForecasts for the crude steel production

0 20 40 60 80 100 0 0.5 1 1.5 2

Asia Oceania

North America

South

AmericaEurope Africa

(billion people) (billion tons)

0.9

O n l y t h e

p o p u l a t i o n g r o w t h i s

t a k e n i n t o a c c o u n t

The economicgrowth of each regionis also takeninto account

1.35 1.95



China

JapanJapan

U.S.A.

Germany Korea

1950 60 70 80 82 84 86 88 90 92 94 96 98 00 02 03

200

180

160

140

120

100

80

60

40

20

0

Total

1000

800

600

400

200

0

220

Japanese peak 120 million tons 1973

C r u d e s t e e l p r o d u c t i o n

( m i l l o n t o n s

/ y e a r )

T o t a l p r o

d u c t i o n ( m i l l o n t o n s / y e a

r )



(1957～1970) (1971～1980) (1981～2000)

Top Blow Top Blow

converter converter

degassing degassing degassing degassing degassing

degassing Inclusion Inclusion

control control

Top-bottom

comvined converter

Top-bottom

comvined converter



0

1

2

3

4

5

1 9 7 4

1 9 7 6

1 9 7 8

1 9 8 0

1 9 8 2

1 9 8 4

1 9 8 6

1 9 8 8

1 9 9 0

1 9 9 2

1 9 9 4

1 9 9 6

1 9 9 8

2 0 0 0

2 0 0 2

M n a l l o y u n i t ( k g

/ t )

HC-FeMnMC,LC

Si-Mn

M.Mn

Fe-Si

0

1

2

3

4

5

6

7

1 9 7 4

1 9 7 6

1 9 7 8

1 9 8 0

1 9 8 2

1 9 8 4

1 9 8 6

1 9 8 8

1 9 9 0

1 9 9 2

1 9 9 4

1 9 9 6

1 9 9 8

2 0 0 0

2 0 0 2

M n u n i t (

k g / t )

TotalHC-FeMn

MC,LC Fe-Mn, M.Mn, Si-Mn



1. Introduction

3. History of Process Improvement and




(4) MURC process


(2) Plate products




Process Flux & oxygen ％ content in Fe

[C] [Si] [P] [S] [Mn] Temp.

（℃）

BF 1530

(dS) CaO、 4.5 0.4 0.1 0.02 0.3

Hot Metal Mg or Na2CO3

Pretreatment (dP) CaO、

Fe-Ore、O2 4 ｔｒ 0.02 0.005 0.2 1350

BOF CaO、MgO

Mn-Ore

Fe-Ore、O2 0.05 tr 0.02 0.005 0.15 1650

Secondary

Refining Alloy

0.001 tr 0.005 0.001 0.15～

Product ～0.3 ～0.5 ～0.03 ～0.03 1.5 -

Reaction Condition

Basicity PO2 Temp.

Decarburization - High -

Dephosphorization High High Low

Desulfurization High Low High

Reduction of MnO High Low High

An example of the steel making method &

acceleration conditions for respective reactions.

C ＋ 1/2O２＝ CO P ＋ 5/4O２＋ 3/2CaO ＝ 1/2Ca３（PO４）２

S ＋ CaO ＝ CaS ＋ 1/2O２

Mn ＋ 1/2O２＝ MnO



[C] [Si] [Mn]

[C] [Si] [Mn][C] [Si] [Mn]

HCFeMn LCFeMn Si-Mn

kg/heat HCFeMn LCFeMn Si-Mn

kg/heat HCFeMn LCFeMn Si-Mn

Yield 95 95 95 ％ kg/heat

95 95 95 ％

95 95 95 ％

Chemical content （％）

C Si Mn

HCFeMn 6.85 0.00 74.50

LCFeMn 0 .86 0.00 81.00

Si-Mn 2.20 14.50 60.70



Mn ＋ 1/2O

2 ＝ MnO

(%MnO) 1

[%Mn] Tlo = -1.79 + 1.07×log (%T.Fe) + 3.980× -0.048×log (%CaO/%SiO2)

1

55 1 （%MnO)

71 1000 [%Mn]

Mn yield （％） =1 + × × × Slag volume

× 100



1. Introduction




(4) MURC process


(2) Plate products




Process Bottom tuyere Bottom gas type Bottom gas flow

construction rate(Nm3/t/min)

LD-OB Double-pipe tuyere O2,Ar,CO2,N2,LPG 0.10 to 0.60

LD-CB Small-diameter pipe CO2,N2,(O2) 0.01 to 0.10

assembly plug

Fig. Relation between turndown free oxygen and turndown carbon intop-blown, bottom-blown, and combined-blown converter 4).

O2

CO2

N2

LPG



O2

CO2

N2

LPG



1. Introduction


(1) Top-and-Bottom blowing converter


(4) MURC process


(2) Plate products




82 84 86 88 90 92 94 96 98 00 02

Nipponn Kimitsu ★ ●

Steel Yawata ★ ●Oita ★ ▲ ●

Nagoya ★ ●

Muroran ★ ●

JFE Chiba ★

Mizushima ★Keihin ▲ ●

Fukuyama ▲ ●

Sumitomo Kashima ★ ●

Wakayama ★ ● ●

Kobe Kakogawa ★ ★

Kobe ●

★：TPC

▲：Ladle

●：Converter



LD Hot metal pretreatment

process and LD-OB process(1981) (1989)

Monthly crude steel production 200,000 407,000

capacity (t/furnace/month)

Hot metal pretreatment ratio (%) 0 69

Availability (%) 55.2 85.5

Tap-to-tap time (min) 34 28

Furnace life (heats) 1,795 5,340

Molten steel yield (%) 93.6 95.1



0

10

20

30

40

5060

70

80

90

100

0 20 40 60 80 100 120



1. Introduction




(4) MURC process


(2) Plate products




Free Exhaust Stirring Oxygen Oxygen Scrap Initial

boad gas energy supplying gas ratio melting investment

treatment rate cost

Injection Process Small Simple Low Low Low Impossible Low

Top-and-bottom Large OG High High High Possible High

blowing converter System

Slag (T.Fe) De-Si Addition of Slag Slag

basicity content before fluorspar foaming utilization

de-P

Injection Process 4-8 2-5 Imperative Necessary Small Difficult

Top-and-bottom 1-2 7-18 Not Not Large Easyblowing converter Imperative Necessary

Process

Treatment condition



Manganese use in the LD-type process

For manganese use in the LD-type process,

manganese yield improvement

due to the decreased slag volume in the converter

can be obtained in the same way as using conventional technology.

However, a decrease in Mn during dephosphorization

cannot be avoideddue to increased %T.Fe and lowered basicity

during dephosphorization.



The [Mn] value

goes down.



1. Introduction






(2) Plate products




Slag

Solidification

ext

chSpeciality of MURC Process

・Low Basicity, High (T.Fe), Low Temperature →High Efficiency De[P]

(CaO/SiO2≦２），(T.Fe)≧8%，（～1350℃）

・High Gaseous Oxygen Ratio,

Low HMR Operation

・Slag Hot Recycle→Reduction of Slag



0

20

40

60

80

100

120

Conventional ＭＵＲＣ No

Recycle

ＭＵＲＣ

T o t a l C a O C

o n s u m p t i o n

（ C

o n v e n t i o n a l

B l o w ＝１００％）

Hot Metal [Si]=0.42%

Low C Steel



20

30

40

50

60

70

80

90

Conventional ＭＵＲＣ No

Recycle

ＭＵＲＣ

B O F S l a g ( k g / t )

Hot Metal[Si]=0.42%

Low C Steel

（Exclude Metal ,Water ）

M l i th MURC



Manganese loss in the MURC process

Manganese loss in the MURC process increases

as a result of low basicity and high %T.Fe

during the dephosphorization process.

In addition, with dephosphorization and decarburization

being operated continuously,

the carry-over of phosphorus into the decarburization process increases,

requiring light dephosphorization treatment

in the decarburization process.

Since the smelting reduction of manganese ore

becomes difficult with increased manganese loss,

the turn-down [Mn] is consequently reduced

compared to that in the conventional pretreatment process.

Manganese alloy in the LD type pretreatment &



Manganese alloy in the LD-type pretreatment &

MURC process

In the LD-type pretreatment method,

priority is given to using scrap and reusing or reducing slag,

which is demanded by today’s society.

On the other hand,

the MURC process focuses on improving heat loss

and shortening the process time.

Neither technology emphasizes

reducing the volume of the Mn alloy used,

So there is little or no reduction

compared to the conventional pretreatment.



1. Introduction

2. Behavior of Mn in the Steel-making process3. History of Process Improvement and



(3) LD-type hot metal pretreatment (4) MURC process

(1) Automobile sheet steel

(2) Plate products




Steel product needs

• Market demands related to steel products are becoming

increasingly strict.

• There has been continuous cost reduction in the refining

process and cost increase due to improved and upgraded

quality of steel products.

→We shall examine the changes in improved and upgraded

steel products using automobile sheet steel and heavy plate products as example.



1. Introduction





(2) Plate products




Application of TS 590 Mpa or

higher steel to automobile 13).



Conventional high strength sheet steel

for automobiles used to be solid

solution-hardened steel or

precipitation-hardened steel withalloy added.

Currently, high strength steel products whose

microstructure isreinforced for greater strength have been used.

(DP steel, TRIP steel)



Yield Tensile Elon-

Type of steel C Si Mn Ti strength strength gation(Mpa) (Mpa) (%)

A Mild steel 0.05 0.01 0.24 - 241 384 43

B Solid solution 0.08 0.02 1.46 - 370 487 30

hardened steel

C DP steel 0.05 0.89 1.25 - 432 618 27

D Precipitation 0.09 0.01 0.80 0.07 539 636 22

hardened steel

E TRIP steel 0.15 1.48 0.99 - 510 644 37



1. Introduction


Influence on Manganese





(2) Plate products



C l i



Conclusion

As for manganese use in the process in view of the above prospects,

we can assume that the smelting reduction of manganese ore

in the converter will not be actively employed in the futuresince it decreases the scrap usage rate, increases slag generation

and results in a low yield level of manganese;

this is on the condition that the Fe-Mn price remains very economical.

As long as the main technological concern in the refining process

focuses on improving the main reaction, namely dephosphorization,

the supply of manganese that has different reactive characteristics

will take the form that adds alloys.



The advantages of steel materials over other materials

include volume, price, strength, toughness and versatility.

For the above sheet steel and plate products,the need for higher grade, higher quality,

and meeting strict requirements will grow in the steel market.

The base for developing higher grade, higher quality steel products

will be the addition of alloys to steel materials.

Fe-Mn alloys, especially low carbon alloys,

will be in much greater demand from now.

References



References

1）Kohtani,T.：IISI 21 Annual Meeting & Conference, Report of Proceedings. 1987,p3

2）Ferroalloy Handbook, Japan Ferro alloy association.

3） Nakamura,K.： 7th International Ferroalloy Conference, (1995)

4）Endoh,K.： Nippon steel technical report No.61 (1994),p.1.

5）

Tada,M. and Masuda,S.：

Tetsu-to-Hagane, 65(1979), S675.6）Handbook of Iron and Steel 4th edition (2002), The Iron and steel Institute of Japan.

7）Tabuchi,S et al：Proceedings of the 6th International Iron and Steel Congress (1990),p57.

8）Kitamura,S. et al： 9th China-Japan Symp. on Sci. & Tech. of Iron and Steel Program, Nov.(2001).

9）Tomita,K. et al：3rdEuropean Oxygen Steelmaking Conference, Nov.(2000),p59.

10) Shima,H. et al：2nd European Oxygen Steelmaking Congress, Italy, Oct. (1997).

11) Kumakura,M.：127th Seikou-bukai ,(2002), The iron and steel Institute of Japan.

12) Kuriyama,Y. et al：Journal of Society of Automotive Engineers of Japan, Vol.55,No.4 (2001), p.51.

13) Yukihisa Komiya： Kobe steel engineering reports Vol.52 No.3 (Dec.2002) P.2.

14) Itoh,S. et al：Bulletin of the iron and steel Institute of Japan, Vol.4, No.6 (1999), p.367.

15) Uenishi.A, et al.： Nippon steel technical report No.81 (2000),p.18.

16) Amano,K.：Bulletin of the iron and steel Institute of Japan, Vol.8(2003)No.10,p.21

17) Advanced Technology of Plate Production in Japan, The iron and steel Institute of Japan ,(1984) p116.

05- new and future steel technologies using mn - k ichikawa nippon steel corp

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