METHOD OF TREATMENT OF ROLLED PRODUCTS OF CARBON AND LOW-ALLOY STEELS Russian patent published in 1995 - IPC

FIELD: ferrous metallurgy. SUBSTANCE: method comprises steps of rolling a billet of carbon or low-alloy steel had been heated in a heating furnace up to rolling temperature, in stands of continuous merchant bar or rod rolling mill for making round cross section rolled stock of predetermined size. After hot rolling the ready rolled product at outlet of the final stand of the mill is being fed to a plant for preliminary cooling of it (first cooler) for achieving a preliominary cooling of surface of the rolled stock to temperature T_p,, being determined according to an expression , where T_p-temperature of the rolled stock surface, C; T-temperature of the metal before cooling it, C; t- time period of cooling, s; d diameter of the rolled stock, mm; curing the rolled stock, had been preliminary cooled up to sustenization temperaturem that is to temperature value, equal to Ac₃-(Ac₃+ 50^°C), in a zone for levellling temperature between the plant for preliminary cooling and a route for rapid cyclic cooling. The rolled stock, had been passed through the zone for levelling temperature, is being fed to the route for rapid cyclic cooling with a cooling rate (250-500)C/s and with a cycle period 0.1-0.3 s up to a weighted mean temperature (650-750) C. The rolled stock is being finally cooled in air. EFFECT: simplified treatment process. 1 cl