high strength cold rolled steel plate having elastic limit with low planar anisotropy and method for producing it

摘要

High strength cold rolled steel plate having elastic limit with low planar anisotropy and method for its production. The invention relates to a high-strength cold-rolled steel sheet having low planar anisotropy yield strength and excellent press-forming ability having a composition including (by weight%), c: 0.06% at 0 ° C. , 12%; si: 0.7% or less; mn: 1.2% to 2.6%; p: 0.020% or less; s: 0.03% or less; there sol .: 0.01% to 0.5%; n: 0.005% or less; the balance being fe and the inevitable impurities. The steel plate includes, in terms of volume fractions with respect to the entire microstructure, 60% or more of ferrite phase as main phase, and 5% or more and 20% or less of martensite phase, and has a distribution function. 3d crystal orientation of 2.5 or less at {cpi, l, p2} = {00 350 450}