Production method of 590MPa-grade formability-enhanced hot-dip galvanized dual-phase steel

Abstract

The invention provides a production method of 590MPa-grade formability-enhanced hot-dip galvanized dual-phase steel. C-Si-Mn-Al-Ti is adopted as a basic alloy system, a certain amount of stable retained austenite is introduced on the basis of a traditional dual-phase steel ferrite and martensite microstructure at a low alloy cost, and through the TRIP effect generated by the retained austenite in the deformation process and optimization to the processes of finish rolling, continuous annealing and galvanizing, the product mechanical properties meet the conditions that the yield strength is 380-390 MPa, the tensile strength is 625-640 MPa, the ductility is 27-29%, and the n value is 0.16-0.18. The galvanized surface is uniform in color and free of defects, an inhibition layer is continuous and compact, zinc layer adhesive force ball punching reaches the first level, the coating and steel base bending experiment is qualified, and the complex part forming requirement and the surface quality requirement are met.

Description

Technical field [0001] The present invention relates to the field of rolling steel, and more particularly to a production method of 590 MPa-level reinforced molded hot-dip galvanized double phase steel. Background technique [0002] In order to realize the use of car safety, improve car safety, advanced high-strength steel in the white car is increasing, and the double phase steel has become the largest steel from advanced high-strength steel due to good comprehensive mechanical properties. However, the strength of the steel sheet is improved, which is usually caused to form a complex stamped structure of the automobile, and the traditional DP steel is difficult to form on many high-alted parts, and it is difficult to meet the complex stamped structural parts of the automobile, and use TRIP steel Then lead to a high alloy content, severe welding problem, and the elongation is wasteful. Therefore, DP steel having a TRIP effect is developed, and high ductility DP steel has good eco...

AI Technical Summary

Problems solved by technology

[0003] At present, the existing technology improves the drawing performance by adding different alloy elements on the basis of the traditional dual-phase steel DP590, and clarifies the production method, processing method or manufacturing method, such as the patent with the publication number CN111172466A; or by adjusting complex process parameters To optimize the structure of dual-phase steel DP590, the complex process parameter setting is limited to trial production in the laboratory, and is not suitable for mass production in factories, such as the patent with publication number CN111549273A

Images