STRUCTURAL STEEL Russian patent published in 1994 - IPC

FIELD: ferrous metallurgy. SUBSTANCE: steel has the composition as follows (per cent by weight): 0.25 - 0.45 carbon, 0.17 - 0.37 silicon, 0.6 - 1.20 manganese, 0.6 - 1.20 chromium, 0.02- 0.12 vanadium, 0.02 - 0.06 aluminium, 0.005 - 0.012 nitrogen, 0.015 - 0.05 titanium, 0.0008 - 0.005 boron, 0.0008 - 0.005 calcium, 0.04 - 0.4 copper, 0.0008 - 0.005 barium, the balance being iron with 10-40×10^-5 aluminium-to-nitrogen ratio. EFFECT: required level and deep of hardenability, and 45 - 55 HRC surface hardness for parts after hardening heat treatment. 2 tbl