| 摘要 |
PROBLEM TO BE SOLVED: To suitably treat an object to be treated comprising a high tensile strength steel sheet at least on a part since the high tensile strength steel sheet can efficiently be subjected to chemical conversion treatment, and also, harmful effect is not exerted to steel sheets other than the high tensile strength steel sheet. SOLUTION: In the metal surface treatment method, the metal surface of the object to be treated is treated with a phosphate chemical conversion treatment liquid. The treatment is performed at≤47°C. The phosphate chemical conversion treatment liquid has a zinc concentration of, by mass, 1,200 to 2,000 ppm and a fluorine ion concentration of 500 to 1,200 ppm or more. In the metal surface treatment method, at least a part of the object to be treated consists of a high tensile strength steel sheet. COPYRIGHT: (C)2004,JPO
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