STEEL Russian patent published in 1994 - IPC

FIELD: metallurgy. SUBSTANCE: in order to improve cooling resistance of high-strength steel in the state after hot rolling with accelerated cooling while maintaining the at least 600 N/mm², steel further comprises nickel and niobium, the ratio of the components being as follows (wt %): 0,06-0,15 carbon; 0.1-0.5 silicon; 1.5-2.2 manganese; 0.3-0.8 chromium; 0.02-0.10 vanadium; 0.01-0.05 titanium; 0.01-0.08 aluminium; 0.001-0.010 calcium; 0.006-0.014 nitrogen; 0.3-0.7 nickel; 0.01-0.05 niobium; and iron, the balance, the ratio of the components being as follows: 600≥ 830-270 carbon: 90 manganese : 37 nickel : more than 550 chromium; 0.13≥ carbon : 12/93 niobium : 12/51 vanadium 12/48 (titanium 3.4 nitrogen) > 0.03. EFFECT: improved properties of the steel. 2 tbl