| 摘要 |
PROBLEM TO BE SOLVED: To provide a treating method forming a chemical conversion coating having excellent corrosion resistance for a high-tensile steel sheet by a phosphating treatment. SOLUTION: In the method for treating the high-tensile steel sheet, the high- tensile steel sheet is treated by using a phosphate chemical conversion treatment solution having, by weight, 1,200 to 1,500 ppm zinc concentration, <=500 ppm fluorine ion concentration and 1.2 to 1.4 free acidity at >=50 deg.C treating temperature.
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