400MPa high-strength and high-forming-performance cold rolled steel plate and production method thereof

Abstract

The invention discloses a 400MPa high-strength and high-forming-performance cold rolled steel plate, which mainly comprises the following chemical components in percentage by weight: less than or equal to 0.004 percent of C, 0.1 to 0.4 percent of Si, 0.1 to 1.0 percent of Mn, 0.01 to 0.1 percent of P, less than or equal to 0.030 percent of S, 0.01 to 0.05 percent of Al, 0.01 to 0.1 percent of Ti,less than or equal to 0.005 percent of N and 0.0004 to 0.0012 percent of B. By combining rolling, cold rolling and continuous annealing processes, the yield strength of the cold rolled plates reaches210 to 310MPa, the tensile strength is more than or equal to 400Mpa, the coefficient of elongation is more than or equal to 32 percent, the n90 content is more than or equal to 0.15 percent and the r90 content is more than or equal to 1.8; desirable plate shape, surface quality, impact performance and welding performance are ensured; overhigh requirements on production processes are avoided, and the operation is feasible; and the production cost is lowered, and the cold rolled steel plates have high strength and high cold forming performance.

Description

technical field [0001] The invention belongs to the technical field of metallurgical industrial products and their manufacturing techniques, and relates to cold-rolled steel sheets and their manufacturing techniques. More specifically, the invention relates to a 400MPa-level high-strength and high-formability cold-rolled steel sheet product. In addition, the invention also relates to The invention relates to a production method of the cold-rolled steel plate. Background technique [0002] With the increasing requirements of the automobile industry for light weight such as energy saving, emission reduction, and self-weight reduction, the demand for high-strength cold-rolled steel sheets is increasing day by day, and thin sheets accounting for more than 60% of the weight of automobiles are the key to weight reduction. [0003] Phosphorus-added strengthened cold-rolled high-strength steel plate is currently the most used high-strength cold-rolled plate for automotive panels and...

AI Technical Summary

Problems solved by technology

[0007] The steel provided by these two patented technologies can meet the requirements of deep drawing formability for the manufacture of high-strength steel plates, but there are some shortcomings: 1. The tensile strength is low; 2. A large amount of Nb element is added, and the cost is high