| 摘要 |
Steel for forging comprises by weight 0.05-0.12 (0.05-0.08)%, carbon, 0.1-0.45 (0.15-0.35)% Si, 1.01-1.8 (1.01-1.35)% Mn, 0.15-1.15 (0.8-1.15)% Cr, 0.06-0.12 (0.08-0.11)% Mo, up to 0.30% each of copper and nickel, 0.01-0.04% titanium, 0.005-0.04% aluminium, 0.006-0.013% nitrogen, 0.0005-0.004% boron, up to 0.025 % phosphorous, 0.02-0.1% sulphur, up to 0.1% lead and up to 0.07% tellurium, optionally 0.002-0.002% calcium and the remainder iron and incidental impurities. The sum of Ni, Mo and Cu falls in the range 0.2-0.07%, and there is at least 0.005% of non-combined B at above 950 degrees C. Also claimed are a forging method and a forged piece of the steel exhibiting certain mechanical characteristics. |
