METHOD OF STEEL COMPLEX HEAT TREATMENT

摘要

FIELD: metallurgy.SUBSTANCE: steel workpiece containing carbon in amount of 0.15-0.25 wt % and manganese in amount of 1.2-1.7 wt % is heated to complete austenitising structure. Then, it is cooled in furnace to curing temperature of 735-740°C or in air to room temperature with further heating to said curing temperature of 735-740°C. Note here that curing is executed for formation of two-phase austenite-ferrite structure while cooling after curing is performed at the rate allowing incomplete martensitic of austenite and formation of multiphase microstructure. Thereafter, high-temperature tempering-ageing at 550°C is carried out for 2-2.5 hours. Before heating to complete austenitising preliminary normalisation at temperature from 930°C.EFFECT: high and stable mechanical properties.2 cl, 1 tbl, 3 dwg