| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for easily and inexpensively producing a high-tensile strength cold rolled steel sheet having excellent corrosion resistance after coating which has a tensile strength (TS) of≥590 MPa. <P>SOLUTION: Regarding the method for producing a high-tensile strength cold rolled steel sheet having excellent corrosion resistance after coating whose tensile strength is≥590 MPa, a steel sheet after cold rolling comprising, by mass, 0.05 to 0.25% C, 0.8 to 2.4% Si, 1.0 to 3.0% Mn,≤0.10% P and 0.01 to 0.10% Al, and the balance Fe with inevitable impurities is subjected to continuous annealing, and is thereafter pickled for 5 to 30s in a pickling solution at 20 to 80°C comprising a sulfur compound, thus a metal sulfate is formed on the surface of the steel sheet, and further, the sulfide of 0.5 to 100 mg/m<SP>2</SP>expressed in terms of an S content is stuck thereto. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
