METHOD OF THERMOMECHANICAL TREATMENT OF ROLLED PRODUCTS

ferrous metallurgy, particularly, manufacture of heat-hardenable reinforcing bar steel in heavy sections with use of rolling heat in heat hardening of rolled products in set of medium-section mills. SUBSTANCE: technology of thermomechanical treatment of rolled products, mainly of reinforcing bars of heavy sections with use of rolling heat, includes hot rolling, preliminary cooling of feed to temperature of not below Ar3, final rolling in this region of temperatures, cyclic cooling of surface with number of cycles equaling two, with intermediate and final warming of surface. In so doing, the first cycle of feed surface cooling is carried out of temperature 50 C below or equal to temperature of minimal stability of deformed austenite with intermediate warming of surface to temperatures 50-150 C above temperature of minimal stability of deformed austenite. The second cycle of surface supercooling is carried out to temperature of 100-200 C below Mn with final worming of surface to temperature below Acl point and final cooling. EFFECT: high strength and ductility characteristics of steels not containing expensive and difficulty available elements such as Mn, Ni and others, and possible making of high-strength reinforcing bar steels in heavy section. 1tbl