| Equivalent grades |
GB |
DIN |
AISI |
JIS |
|
| 42CrMo |
1.7225 |
4140 |
SCM440 |
|
| Chemical Composition |
C |
Si |
Mn |
Cr |
Mo |
P |
S |
|
| 0.38-0.43 |
0.40max |
0.60-0.90 |
0.90-1.20 |
0.15-0.30 |
0.035max |
0.035max |
|
| Available size |
Round Bar |
Diameter |
Length |
| 70-600mm |
2000-6000mm |
| Flat Bar |
Thickness |
Width |
Length |
| 25-400mm |
200-800mm |
2000-6000mm |
| Surface condition |
Black surface/ Grinded/ Machined |
| Annealed hardness |
HBS≤217 |
| Characteristics |
special alloy steel, engineering steel supplied in quenched and tempered conditions. Very good machinability. High toughness. High creep strength. Repeated impact resistant capability. |
| Applications |
components with high requirements on toughness, e.g. gear wheels, pinions, connecting rods, parts for mechanical engineering |
| Heat Treatment |
Forging |
Heat to 1150℃. Hold until uniform. Minimum forging temperature 850℃。Cool slowly in ashes or sand etc. |
| Annealing |
Heat to 830℃-850℃。Cool in furnace. |
| Normalising |
Heat to 870℃-900℃。Cool in still air. |
| Stress Relieving |
Annealed: Heat to 600℃-650℃。Hardened: Heat to 500℃-550℃。Cool in still air. |
| Hardening |
Heat to 830℃-880℃. Quench in oil or polymer. |
| Tempering |
Heat to 450℃-700℃ cool in still air. NB. Tempering within the range 200℃-420℃ will result in temper brittleness and should be avoided. |
