STEEL AND ITS VARIANTS Russian patent published in 1997 - IPC

FIELD: metallurgy, particularly, composition of steel for pump rods being manufactured of 0!!!16-40 mm bar which is thermally strengthened by cooling on open air. SUBSTANCE: steel comprises, mas.%: carbon, 0.08-0.14; manganese, 0.9-1.6; chromium, 2.0-3.2; vanadium, 0.05-0.3; nitrogen, 0.006-0.10; ferrum, the balance; ratio of carbon and vanadium content in it is to be within 0.4-2.4 ranges. Also steel may comprise, mas.%: carbon, 0.08-0.14; manganese, 0.9-1.6; chromium, 2.0-3.2; vanadium, 0.05-0.30; niobium not more 0.02; nitrogen, 0.006-0.10; ferrum, the balance; ratio of carbon and vanadium content in it is to be within 0.4-2.4 ranges and vanadium content and niobium content in it is to fulfil following ratio: 10 Nb + V = 0.05-0.30. EFFECT: provides high strength in steel half-finished articles being thermally strengthened by cooling on open air without crack formation. 3 cl, 2 tbl