GB 40CR alloy Steel is a high quality Quenched and Tempered Alloy Structural steel, It belong to the high quality low carbon,Low alloy chromium, molybdenum, nickel case hardening steel. Oil Quenched & Tempered Hardness is 28-34 HRc. GB 40CR steel Annealing delivery hardenss less than 250HB. 40CR With a lower carbon content range, So GB 40CR alloy steel have good weldability.
GB 40CR Alloy steel, we can supply the round bar, seamless steel tube, hard chrome bar. GB 40CR steel Round bar can be sawn to your required lengths as one offs or multiple cut pieces.
Chemical composition
| C(％) | 0.37～0.44 | Si(％) | 0.17～0.37 | Mn(％) | 0.50～0.80 | P(％) | ≤0.030 |
| S(％) | ≤0.030 | Cr(％) | 0.80～1.10 |
Equivalent Of 40Cr alloy Structure Steel
| USA | Germany | China | Japan | France | England | Italy | Poland | ISO | Austria | Sweden | Spain |
| ASTM/AISI/UNS/SAE | DIN,WNr | GB | JIS | AFNOR | BS | UNI | PN | ISO | ONORM | SS | UNE |
| 5140 / G51400 | 41Cr4 / 1.7035 | 40Cr | SCr440 | 42C4 | 530A40 / 530M40 | 41Cr4 | 2245 | ||||
Heat treatment Related
- Annealing of 40CR Alloy structural steel
Slowly heated to 850 ℃ and allow enough times, let the steel to be thoroughly heated, Then cool slowly in the furnace. The 40CR alloy steel will get MAX 250 HB （Brinell hardness）.
- Hardening of 40CR Alloy structural steel
Heated slowly to 880-920°C, Then after adequate soaking at this temperature quench in oil. Temper as soon as tools reach room temperature.