Patent ID: 9512508
Filing Date: 2016-12-06
CPC Classification: C21D,C22C,Y10T

Claim Text:
1. A high-strength cold-rolled steel sheet having excellent stretch flangeability and precision punchability comprising: in mass %, C: greater than 0.01% to 0.4% or less; Si: not less than 0.001% nor more than 2.5%; Mn: not less than 0.001% nor more than 4%; P: 0.001 to 0.15% or less; S: 0.0005 to 0.03% or less; Al: not less than 0.001% nor more than 2%; N: 0.0005 to 0.01% or less; and a balance being composed of iron and inevitable impurities, wherein in a range of ⅝ to ⅜ in sheet thickness from the surface of the steel sheet, an average value of pole densities of the {100}<011> to {223}<110> orientation group represented by respective crystal orientations of {100}<011>, {116}<110>, {114}<110>, {113}<110>, {112}<110>, {335}<110>, and {223}<110> is 6.5 or less, and a pole density of the {332}<113> crystal orientation is 5.0 or less, and a metal structure contains, in terms of an area ratio, greater than 5% of pearlite, the sum of bainite and martensite limited to less than 5%, and a balance composed of ferrite.