Influence of Intermittent Quenching and Self-Tempering on the Mechanical Properties of Rebar Steel

The influence of deformation and heat treatment on the mechanical properties of rebar steel is investigated on a pilot system. Specifically, with intermittent quenching and subsequent self-tempering, the intense-cooling time determines the tempering temperature of the quenched steel and hence the final mechanical properties of the rebar. The influence of the water pressure in the intense-cooling chamber on the uniformity of the mechanical properties is studied for steel with 0.31, 0.32, and 0.35% C; the water pressure is varied from 0.2 to 0.6 MPa. On that basis, it is established that the water pressure in the cooling chamber must be no less than 0.3 MPa, and the carbon content in the steel must be more than 0.32% in order to ensure that the mechanical properties of the rebar steel conform to the AT500 strength class according to State Standard GOST 10884–2004.