METHOD OF HEAT TREATMENT OF CASTINGS FROM LOW DUCTILITY STEELS Russian patent published in 2000 - IPC

FIELD: metallurgy, particularly, heat treatment of cast steels with low ductility, including steels of ledeburitic class. SUBSTANCE: method includes cooling of casting from temperature of beginning of crystallization, and annealing. Crystallization is combined with annealing by introduction of controlled cooling of solidifying casting in form of multiple successive alternation of short-time pulses of chilling of casting surface at rate of 700-900 C/s with pulses of warming so that after each next pulse of warming, casting surface temperature continuously drops. In so doing, alternation of CHILLING-WARMING pulses is continued until temperature of completion of eutectoid conversion for steel of given composition. Further on, cooling is not monitored. Casting are produced by steel casting into ingot mold or in metal mold, or by continuous casting. Warming is carried out with help of own heat of central zone of casting, or heat from external heat source. EFFECT: extended range of engineering means directed for provision of high ductility in hot deformation of low-ductility steels. 3 cl, 2 ex