METHOD OF IMPROVING HEAT TREATMENT OF STEEL Russian patent published in 1999 - IPC

FIELD: metallurgy and mechanical engineering. SUBSTANCE: for rolling and forging steel is hardened from temperature of rolling end or stamping heating with cooling rate at which structure of grainy bainite is formed. Process is regulated by corresponding selection of steel composition and cooling conditions. Then blanks are machines and tempered at 100-600 C for at least 1.5 h. Long-sized parts and parts with complicated shape are hardened from separate heating by cooling at rate to form grainy bainite. Process is regulated by corresponding selection of steel composition and cooling conditions. Then part is tempered at 100-600 C for at least 1.5 h. As a result of tempering at 100-600 C for 1.5 h, after hardening from temperature of rolling or stamping heating, or separate heating, structure of grainy sorbite or grainy pearlite, depending on tempering temperature is formed. EFFECT: higher efficiency of method with preservation of complex of steel mechanical properties corresponding to complex of mechanical properties obtained at improving heat treatment of steel. 1 dwg, 1 tbl