STEEL Russian patent published in 1998 - IPC

FIELD: metallurgy, ferrous-base alloys. SUBSTANCE: steel containing carbon, silicon, aluminium, manganese, chrome, molybdenum, titanium and iron has additionally cerium at the following ratio of components, wt.-%: carbon, 0.06-0.13; silicon, 0.15-0.40; manganese, 0.30-0.60; chrome, 0.40-0.70; molybdenum, 0.08-0.15; aluminium, 0.01-0.07; titanium, 0.005-0.09; cerium, 0.002-0.05; and iron, the rest. Cerium content in each case of steel composition is determined depending on aluminium and titanium content by the following formula: [Ce] ≥ 2.5 x 10^-4 ([Al] + 0.8 [Ti] where [Ce], [Al], [Ti] - cerium, aluminium and titanium content, respectively. Simultaneous addition of aluminium, titanium and cerium in combination with other elements to steel at indicated ratios provides high strength of steel to sulfide cracking in hydrogen sulfide medium, good weldability under conditions of low temperatures and satisfactory resistance to wear. EFFECT: improved quality and properties of steel. 1 tbl