|
Min. % |
Max % |
| Carbon |
0.42 |
0.49 |
| Silicon |
0.15 |
0.35 |
| Manganese |
0.65 |
1.10 |
| Chromium |
0.75 |
1.20 |
| Molybdenum |
0.15 |
0.25 |
| Phosphorous |
0 |
0.035 |
| Sulphur |
0 |
0.04 |
| Nickel |
0 |
0.25 |
| Copper |
0 |
0.35 |
| Mechanical Property Requirements for Steels in the Heat-Treated Condition for Peeled, Black Bar |
| Mechanical Property Designation |
API - 7 |
| Limited Ruling Section mm |
|
| Tensile Strength Mpa |
Min |
970 |
| Max |
|
| 0.2% Proof Stress Mpa |
Min |
755 |
Elongation on
5.65√S0 % |
Min |
13 |
| Izod Impact J |
Min |
|
| Charpy Impact J |
Min |
54 |
| Hardness Brinell HB |
Min |
|
| Max |
341 |
|
| Forging |
Heat to 1200 oC maximum, hold until temperature is uniform throughout the section.
Do not forge below 950 oC. |
| Heat Treatment |
| Annealing |
| Heat to 815 oC - 850 oC, hold until temperature is uniform throughout the section. |
| Flame or Induction Hardening |
|
| Hardening |
| Heat to 820 oC - 870 oC, hold until temperature is uniform throughout the section. Quench in oil as required. |
| Nitriding |
|
| Normalizing |
| Heat to 870 oC - 900 oC, hold until temperature is uniform throughout the section, soak for 10 - 15 minutes and cool in still air. |
| Stress Relieving |
|
| Tempering |
| Re-heat to 430 oC - 700 oC as required and according to properties required. |
| Notes on Heat Treatment |
|
| Machining |
|
| Welding |
| Best results by common fusion or resistance methods. Do not weld by oxyacetylene. |
