Controlled rolling and cooling method for PSB830 fine rolled threaded steel

Abstract

The invention discloses a controlled rolling and cooling method for PSB830 fine rolled threaded steel. The controlled rolling and cooling method comprises the steps that (1) a PSB830 steel billet is heated and then is subjected to rough rolling, intermediate rolling and finish rolling in sequence; (2) the rolled PSB830 steel is subjected to through-water cooling through a first through-water cooling area, a second through-water cooling area, a third through-water cooling area, a fourth through-water cooling area and a fifth through-water cooling area in sequence; and (3) air cooling is conducted after tempering, the water pressure of cooling water in the first through-water cooling area is 0.7-1.1 MPa, the water pressure of the second through-water cooling area is 0.8-1.2 MPa, the water pressure of the third through-water cooling area is 1.0-1.4 MPa, the water pressure of the fourth through-water cooling area is 1.0-1.4 MPa, and the water pressure of the fifth through-water cooling area is 0.7-1.1 MPa. The effects that a surface layer quenching martensitic structure is effectively avoided, transformation of the structure type is achieved, and meanwhile, good uniformity of the surface layer and the core temperature is ensured are achieved.

Description

technical field [0001] The invention relates to the field of steel rolling technology, in particular to a method for controlled rolling and controlled cooling of PSB830 finish-rolled rebar. Background technique [0002] In the steel rolling process, the rolling and cooling processes have a very important impact on product performance and production costs. Controlled rolling and cooling can improve the mechanical properties of products, reduce production costs, save energy and protect the environment. For example, in the production process of alloy steel, controlled rolling and controlled cooling can obtain ultra-fine grains, and can greatly improve its mechanical properties; , Control the band structure, reduce oxidation, etc., and partially replace the heat treatment process to meet product performance requirements. [0003] After traditional bar rolling, rapid cooling is often used to realize the waste heat treatment process, that is, the steel bar with the final rolling ...

AI Technical Summary

Problems solved by technology

[0006] In view of the above-mentioned prior art, the purpose of the present invention is to provide a method that satisfies the mechanical properties of the steel, can solve the problems of poor performance under the traditional process, and can effectively avoid the appearance of the surface quenched martensite structure, and realize the structure type. The controlled rolling and cooling method of PSB830 finish-rolled rebar, while ensuring the uniformity of surface and core temperature