LOW-HARDENING STRUCTURAL STEEL Russian patent published in 2000 - IPC

FIELD: structural steel with low hardenability applicable in use of steel bulk-surface hardening method developed and found industrial application in Russia for hardening of critical, heavily loaded machine parts. SUBSTANCE: claimed steel contains carbon, manganese, silicon, chrome, nickel, titanium and iron and additionally contains copper, aluminum and vanadium with the following amounts of components, wt.%: carbon 0.40- 0.85; manganese not above 0.20; silicon not above 0.20l chrome not above 0.10; nickel not above 0.10; copper not above 0.10; aluminum 0.03-0.10; titanium 0.06-0.12; vanadium not above 0.40; the balance, iron. EFFECT: guaranteed stability of low hardenability and obtained superfine grain of hardened steel at level of 11-12 points with hardening from temperatures from Ac₃ to Ac₃+100 C. 1 tbl, 4 ex