HIGH-STRENGTH COLD-ROLLED STEEL SHEET HAVING EXCELLENT STRETCH FLANGEABILITY AND PRECISION PUNCHABILITY AND MANUFACTURING METHOD THEREOF

摘要

A high-strength cold-rolled steel sheet having excellent stretch flangeability and precision punchability which contains given components, with the remainder comprising iron and incidental impurities. In the range of from a depth from a surface of the steel sheet which corresponds to 5/8 the sheet thickness to a depth therefrom which corresponds to 3/8 the sheet thickness, the average pole density for {100}<011> to {223}<110> orientations which are represented by the crystal orientations {100}<011>, {116}<110>, {114}<110>, {113}<110>, {112}<110>, {335}<110>, and {223}<110> is 6.5 or less and the pole density for the crystal orientation {332}<113> is 5.0 or less. The steel sheet has a metallographic structure that contains pearlite in an amount exceeding 5% in terms of areal proportion and has a total content of bainite and martensite limited to below 5% in terms of areal proportion, with the remainder comprising ferrite.