METHOD FOR PRODUCING COLD-ROLLED STEEL SHEET, COLD-ROLLED STEEL SHEET, AND VEHICLE MEMBER

摘要

This invention provides a method of producing a cold-rolled steel sheet being excellent in not only the phosphate treatability but also the corrosion resistance after coating under severe corrosion environment such as hot salt water immersion test or composite cycle corrosion test, wherein a continuously annealed steel sheet after cold rolling preferably comprising 0.5-3.0 mass% of Si is pickled to remove a Si-containing oxide layer on a surface layer of the steel sheet and further repickled so that a surface covering ratio of an iron-based oxide on the surface of the steel sheet is not more than 40% and preferably a maximum thickness of the iron-based oxide is not more than 150 nm, as well as a cold-rolled steel sheet produced by this method and a member for automobile using the cold-rolled steel sheet.