casting powder for special steel grades - 1und1.de

Casting Powder for Special Steel Grades


2

Main Focus Steel Grades

• Ultra Low Carbon ( ULC )• Low Carbon ( LC )• Peritectic• Medium Carbon ( MC )• High Carbon ( HC )


3

Ultra Low Carbon (IF - Grades)• %C = < 0,02• Internal cleanness• Automobile, Cans, Pots

Casting Powder• Accutherm ST-SP/234-WBV• Low carbon content < 3% in order to avoid recaburisation• Medium basicity ( < 1 ) in order to avoid hook formation in the meniscus area• Higher viscosity (~ 0,20 Pa*s) in order to avoid slag inclusions


4

Low Carbon• %C = 0,02 – 0,07• Internal cleanness• Automobile bodies, buildings, pipes

Casting Powder• Accutherm ST-SP/220-A• Low basicity ( 0,85) in order to ensure a high heat extraction for sufficient thick strand shell growth • Low viscosity (0,09 Pa*s) for a good lubrication behaviour, which is of importance because of higher casting

speeds up to 1,5 m/min


5

Peritectic• %C = 0,08 – 0,15• Surface cracks, internal cracks• buildings, bridges, forging

Casting Powder• Accutherm ST-SP/625; Accutherm ST-SP/616AM (> 1,0 vc) • High basicity (~ 1.25) to ensure a reduced and uniform heat extraction in order to avoid strong shrinkage

caused by the delta-gamma transformation• Low viscosity (~ 0.10) to maintain a sufficient lubrication


6

Medium Carbon• %C = 0,16 – 0,21• Surface cracks, segregation• Gears, screws, shafts

Casting Powder• Accutherm ST-SP/605-M1• High basicity (1.15) to ensure a reduced and uniform heat extraction for a homogenous solidification• Low viscosity (0.21 P*sec) to maintain a sufficient lubrication


7

High Carbon• %C = > 0,22 • Internal cracks, segregation• Drop forging dies, rock drills

Casting Powder• Accutherm ST-SP/220-A• Low basicity ( 0,85) in order to ensure a high heat extraction due to low shrinkage• Low viscosity (0,09 Pa*s) for a good lubrication behaviour


8

surfa

ce

cr

acks

inte

rnal

cle

anne

ss

Inte

rnal

cr

acks

segr

egat

ion

defect sensitivitygrade

groups

ULC / IF

low carbon

peritectics

medium carbon

high carbon

non critical

critical

very

critical


9

Special Steel Grades• Transformation Induced Plasticity ( Trip )• Twinning Induced Plasticity ( Twip )• Drawn and Wall Ironed ( DWI )• Non-Grain-Oriented ( NGO )• Grain-Oriented ( GO )• Stainless Steel


10

Transformation Induced Plasticity ( Trip )• %C = 0,15 – 0,20 , %Mn = 1,0 – 3,0, %Si = 1,0 – 2,5, %Al = 0,8 – 2,0• Three Face Microstructure (Ferrit – Bainit – Austenit), High Strength + High Formability • Automobil

Casting Powder• Accutherm ST-SP/234-AL4D ( Bas.: 0.55), (Visco.: 0.09 P*sec)• for grades with Al-contents higher than 0,8%.• 3(SiO2)+3(MnO)+6[Al] → 3(Al2O3)+3 [Si]+3[Mn]• Low alumina content and low melting point to ensure a working slag with good lubrication behavior even after

higher Al-pick-up during casting. Mould powders for Trip grades are extremely low in basicity. By reaction of the aluminium in steel with the SiO2 of the mould powder slag the basicity increases to normal values. With that the powder gets working


11

Twinning Induced Plasticity ( Twip )• %C = 0,40 – 0,60 , %Mn = 19 – 25, %Si = 2,0, %Al = 1,0 – 2,0• Surface cracks, internal cracks• Austinite, maximum strength with sufficient deformability for forming processes• Automobil, Car Body especially crumble zone. These materials were developed especially for crash-relevant body shell components

Casting Powder• Accutherm ST-SP/234-AL4D ( Bas.: 0.55), (Visco.: 0.09 P*sec)• for grades with Al-contents higher than 0,8%. • 3(SiO2)+3(MnO)+6[Al] → 3(Al2O3)+3 [Si]+3[Mn]• Low alumina content and low melting point it ensures a working slag with good lubrication behavior even

after higher Al-pick-up during casting.


12

DWI (Drawn and Wall Ironed)

• ULC ( IF grades with low Al )• %C = <0,02, %Al = 0,03• Internal cleanness• Ferrite, deep drawing quality• Cans

Casting Powder• Accutherm ST-SP/234-WBV• Low carbon content < 3% in order to avoid recaburisation• Higher basicity ( < 1 ) in order to avoid hook formation in the meniscus area• Higher viscosity (~ 0,20 Pa*s) in order to avoid slag inclusions


13

Non-Grain-Oriented ( NGO )

• Electrical Steel• %C = 0,002 – 0,02, %Si = 1,0 – 3,5, %Al = 0,1 – 1,0 • Internal cleanness• Silicon significantly increases the electrical resistivity of the steel, Dendritic crystalline structure• Dynamo

Casting Powder• Accutherm ST-SP/234-121C ( Bas.: 0.93), (Visco.: 0.09 P*sec), • Accutherm ST-SP/235-AL4D for higher Al - content ( Bas.: 0.55), (Visco.: 0.09 P*sec)• for grades with Al-contents higher than 0,6%. • Low alumina content and low melting point to ensure a working slag with good lubrication behavior even after

higher Al-pick-up during casting. In order to get a well working slag


14

Grain-Oriented ( GO )

• Electrical Steel• Internal cleanness• %C = 0,002 – 0,004, %Si = 1,0 – 3,5, %Al = 0,013 – 0,02 + Cupper and Nitrogen alloyed• Ferrite, maximum strength with sufficient deformability for forming processes• Trafo

Casting Powder• Accutherm ST-SP/234-121C ( Bas.: 0.93), (Visco.: 0.09 P*sec)• Ferrit, Globular fine grained crystalline structure• For such steel grades we recommend a powder with a high heat transfer due to the typical weak strand box of

such grades.


15

Stainless Steel

• Austenitic, Ferritic, Martensitic, Duplex (Austenitic+Ferritic)• Non-corrosive, min. 10,5 % Cr• Food Industry, Pharmaceutical Industry

Casting Powder• Accutherm ST-SP/810 (Austenitic), Accutherm ST-SP/816 (Feritic + Martensitic), Accutherm ST-SP/832

(Duplex)• Austenitic steel grades are regarded as crack sensitive. Therefore the heat conductivity of the slag film in the

mould must be reduced what is achieved by the high basicity of this material. The viscosity of this material is low to achieve a sufficient lubrication when the liquidus temperature is low.

• Mould powders for ferritic and martensitic steel grades are extremely low in basicity to ensure a high heat extraction due to sensibility of bulging

casting powder for special steel grades - 1und1.de

Documents