Process for manufacturing steel forging

摘要

Steel for forging comprises by weight 0.1-0.4% carbon, 1-1.8% manganese, 0.15-1.7% silicon and up to 1% nickel, 1.2% chromium, 0.3% molybdenum, 0.3% vanadium and 0.35% copper. Optional ingredients are 0.005-0.06% aluminium, 0.0005-0.01% boron, 0.005-0.03% titanium, 0.005-0.06% niobium, 0.005-0.1% sulphur and up to 0.006% calcium,, 0.03% tellurium, 0.05% selenium, 0.05% bismuth and 0.1% lead, the remainder being iron and impurities. Also claimed is hot-forging a component from an ingot of the steel followed by heat treatment to produce a structure comprising at least 15% bainite and at least 20% ferrite perlite.