Hole expandability and Method for producing a galvanized steel sheet balance very good high-strength steel sheet ductility

摘要

PROBLEM TO BE SOLVED: To provide a high-strength steel sheet which is excellent in hole expandability, ductility, etc., and is suitable for automobiles, building materials, household electric appliances, etc.;SOLUTION: The high-strength steel sheet has a composition containing specific amounts of, by mass%, C, Si, Mn, P, S, Al, N, O, and consisting of the balance Fe and inevitable impurities. The steel sheet structure mainly consists of ferrite and hard structure. The crystal orientation difference between any of the ferrite adjacent to the hard structure and the hard structure is 9°, and the tensile maximum strength is ≥540 MPa.;COPYRIGHT: (C)2010,JPO&INPIT