METHOD OF HEAT TREATMENT OF WHEELS Russian patent published in 1999 - IPC

FIELD: heat treatment of rolled products, specifically, manufacture of solid railway wheels. SUBSTANCE: method of heat treatment of wheels in process of their manufacture includes heating of starting billets for deformation, rolling of wheels in hot state, isothermal holding, thermal hardening, annealing, overcooling of wheels, their holding in air and cooling to ambient temperature. In correspondence with invention starting billets and wheels from heating for deformation up to annealing of thermally hardened wheels are subjected to uninterrupted heat treatment with double overcooling and holding in air. In this case wheels after rolling, first cooling and holding in air are heated to austenitizing temperature, after thermal hardening, second overcooling and holding in air combined operations of annealing and isothermal holding are conducted. In process of overcooling of wheels temperature of metal should not drop below 350 C. In this case wheels are heated after rolling to austenitizing temperature from temperature of 350 C, combined technological operations of annealing and isothermal holding are carried out in the course of 3.0-3.5 h and wheels are held in air after overcooling in the course of 0.5-0.8 h. EFFECT: provision for effective removal of hydrogen, increased technical- and-economic indices of their manufacture. 2 cl, 2 dwg, 1 tbl