Ferrous Powder Production

Ferrous Powder production

Mahesh Nipanikar – Höganäs India Pvt :Ltd

Metal Powder Production

● Powder Production:

– Shape

– Particle size

– Size distribution

● Depends on powder production method

Production of Iron Powders

Powder Production

Water-atomisation process – Majorly used

process. ( Plain powders , low alloy powders ,

stainless steels and tool steels)

Sponge iron process – Solid state reduction

of iron ore ( Majorly Fe3O4)

Alloying methods - Premix , organic

bonded mix.

Brazil Belgium India

Japan

China

United Kingdom Sweden Höganäs Sweden Halmstad

North America

Stony Creek

North America

Niagara Falls

North America

SCM

Johnstown

Production Centres

Sponge iron

- Höganäs

Atomisation

-Halmstad

-Stony Creek

-India

-Brazil

High Alloy

-Belgium

-SCM Johnstown

-United Kingdom

Powder production in Sweden

Halmstad Atomising plant

Höganäs Sponge Iron plant

Powder plant

Distaloy plant

Astaloy plant

Customer mixes

Iron powders

Examples:

ASC100.29

ABC100.30

AHC100.29

Examples:

NC100.24

SC100.26

MH80.23

AHC 100.29

Mesh Size

Apparent density (g/cc)

Water-atomising process

1. Selected scrap

2. Arc furnace

3. Liquid steel

4. Injection

5. Atomising

6. Dewatering

7. Drying

8. Magnetic separation

9. Screening

10. Equalising

11. Transportation to Höganäs

A. Tundish

B. Steel stream

C. High pressure water

D. Nozzle

E. Atomised iron powder

Water-atomising process

1. Selected scrap

2. Arc furnace

3. Liquid steel

4. Injectionn powder

Water-atomising process

5. Atomising

1.ected scrap

2. Arc furnace

Liquid steel

4. Injection

A. Tundish

B. Steel stream

C. High pressure water

D. Nozzle

E. Atomised iron powder

● Variables in Atomization

Process:

– Superheat degree of molten

metal.

– Angle of injection of water

– Nozzle size.

– Metal to water ratio

– Water pressure.

Water-atomising process

1. Selected scrap

2. Arc furnace

3. Liquid steel

4. Injection

5. Atomising

6. Dewatering

7. Drying

8. Magnetic separation

9. Screening

10. Equalising

11. Transportation to Höganäs

h pressure water

Atomised iron powders

Examples:

ASC100.29

ABC100.30

AHC100.29

Sponge iron process 1. Reduction mix of coke breeze and limestone

2. Iron ore

3. Drying

4. Crushing

5. Screening

6. Magnetic separation

7. Charging in ceramic tubes

8. Reduction in tunnel kilns, approximately 1200C

9. Discharging

10. Coarse crushing

11. Storage in silos

12. Crushing

13. Magnetic separation

14. Grinding and screening

15. Annealing in belt furnace, 800-900C

16. Equalising

17. Automatic packing

18. Iron ore

19. Reduction mix

20. Control room

Sponge iron process

1. Reduction mix of coke breeze and limestone

2. Iron ore

3. Drying

4. Crushing

5. Screening

6. Magnetic separation

7. Charging in ceramic tubes

8. Reduction in tunnel kilns, approximately 1200C

9.

Sponge iron process

1. Reduction mix of coke breeze and limestone

2. Iron

7. Charging in ceramic tubes

8. belt furnace, 800-900C. Automatic packing

18. Iron ore

19. Reduction mix

20. Control room

Sponge iron process

1. Reduction mix of coke breeze and limestone

2. Iron ore

3. Drying

4in ceramic tubes

8. Reduction in tunnel kilns, approximately 1200C

9. Discharging

Sponge iron process

1. Reduction mix of coke breeze and limestone

2. Iron ore

3. Drying

10. Coarse crushing

11. Storage in silos

12. Crushing

13. Magnetic separation

14. Grinding and screening

15. Annealing in belt furnace, 800-900C

16. Equalising

17. Automatic packing

18. Iron ore

19. Reduction mix

20. Control room

Sponge iron process

1. Reduction mix of coke breeze and limestone

2. Iron ore

3. Drying

4and screening

15. Annealing in belt furnace, 800-900C

16. Equalising

17. Automatic packing

Sponge iron powders

Examples:

NC100.24

SC100.26

MH80.23

Sponge Vs Atomized iron Powders

Mahesh Nipanikar 19 |

Compressibility

5.6

5.8

6.0

6.2

6.4

6.6

6.8

7.0

7.2

7.4

7.6

200 300 400 500 600 700 800 900

Compating pressure (MPa)

Green

den

sity

(g

/cm

3)

ABC100.30

ASC100.29

AHC100.29

SC100.26

NC100.24

MH80.23

Lubricated die

Sponge Vs Atomized iron Powders

Green strength

5

10

15

20

25

30

35

40

200 300 400 500 600 700 800 900

Compating pressure (MPa)

Green

str

en

gth

(M

Pa

)

MH80.23

NC100.24

SC100.26

ABC100.30

ASC100.29

AHC100.29

0.6% Kenolube

Alloying methods

PRE-ALLOYED ASTALOY

DIFFUSION ALLOYED DISTALOY

PRE-MIXED ORGANIC BONDED STARMIX™

Alloying methods Pre-alloyed

Atomization

Advantages:

•No segregation of alloying

elements

•Homogeneous microstructure

Disadvantages:

•Hard to make alloying changes

Pre-alloyed powders- Astaloys

Powder grade Alloying elements Properties

Astaloy Mo 1,5% Mo

High compressibility with

optimal hardenability-->

surface hardened components

Astaloy A 1,9% Ni, 0,5% Mo, 0,25% MnPrimarily for powder forging

Good hardenability

Astaloy 85 Mo 0,85% MoAdvantages as Astaloy Mo,

but less hardenability

Astaloy CrM 3% Cr, 0,5% Mo

Excellent hardenability, high

strength and hardness after

sintering

Alloying methods - Diffusion alloyed

Advantages:

•Higher compressibility than a

pre-alloyed with same

composition

•Low segregation of alloying

elements

Disadvantages:

•Fixed composition

+

Sponge powder Atomised powder

Cu, Ni, Mo Cu, Ni, Mo

+

Mixing

Diffusion alloyed powders

Powder grade Base powder Alloying elements Properties

Distaloy SA SC100.26 1.75% Ni, 1.5% Cu and 0.5% Mo High green strength

Distaloy AB ASC100.29 " High compressibility

Distaloy SE SC100.26 4% Ni, 1.5% Cu and 0.5% Mo High green strength

Distaloy AE ASC100.29 " High compressibility

Distaloy DC-1

(Dimensional control)Astaloy Mo 2.1% Ni (and 1.5% Mo) No DC change with density

Distaloy DH-1

(Direct hardening)Astaloy Mo 2% Cu (and 1.5% Mo) High hardenability

Distaloy HP-1

(High performance)Astaloy Mo 4% Ni, 2% Cu (and 1.5% Mo) Highest mechanical properties

Compressibility

Chemical composition

1,75 % Ni

1,5 % Cu

0,5 % Mo

Alloying methods

PRE-MIXED ORGANIC BONDED STARMIX™

•Easy to change composition

•Segregation

•Product consistency

•Better flow compared to Premix

•Low dusting

•Close to 100% bonding of graphite

Alloying methods

PRE-MIXED ORGANIC BONDED STARMIX™

0,15

0,20

0,25

0,30

0,35

0,20 0,30 0,40 0,50

Carbon content

Dim

en

sio

na

l c

ha

ng

e

0,15

0,20

0,25

0,30

0,35

0,20 0,30 0,40 0,50

Carbon content

Dim

en

sio

na

l c

ha

ng

e