Cold rolled steel plate of high strength with high ratio of performance and excellent ability of forming and production method of the same

摘要

Invention patent: cold rolled steel sheet for high strength with high ratio of performance and excellent ability of forming and production method of the present invention refers to a cold rolled steel sheet having excellent capacity of high strength The conformation, excellent ductility.Excellent ability of expansion of hole and high yield ratio and a method for producing the same.The cold rolled steel plate of high strength contains 0.05% to 0.15% C, 0.10% and 0.90% Si, 1.0% to 2.0% Mn, 0.005% to 0.05% of P, 00050% or less s, 0.01% to 0.10% of AI, 00050% or less. And 0010% 0100% Nb, which are chemical components, on the basis of the mass, the balance being f And the inevitable impurities.It has a microstructure that has a multi-phase structure containing 90% or more of a ferrite phase and 0.5% to less than 5.0% of a phase in a base of martensita volume fraction, the remainder being processing stages to low temperature, and has a right of income of 40% or more.