Quality of СÑ,3Ñп steel reinforcement (class A500S) thermally hardened in a 280 mill

Thermal hardening of СÑ,3Ñп steel rolled in the 280 mill at the LPZ casting and rolling plant is developed, so as to produce reinforcement (diameter 14-18 mm) of strength class A500S according to the STO ASChM 7-93 standard. The strength of the metal, whether supplied to the mill in the hot or cold state, is the result of discontinuous quenching with variation in mean-mass self-tempering temperature within the range 565-575°C. The macrostructure, microstructure, and fine structure of the thermally hardened bar is investigated. The properties of the bar are ensured by the structure formed as a result of hardening and subsequent cooling on the roller conveyer and in the cooling unit: mainly tempered martensite in the surface layer; ferrite and cementite in the core of the bar.[PUBLICATION ABSTRACT]