| 摘要 |
PROBLEM TO BE SOLVED: To provide a tinned steel sheet which has excellent oxidation resistance, and in which a tin oxidized layer is hardly formed, and a production method therefor. SOLUTION: In the thinned steel sheet having excellent oxidation resistance, one side or both sides of a steel sheet are provided with a tinned layer as an under layer, and, as an over layer, a chemical conversion film consisting of phosphate containing chromium hydrated oxide and magnesium ions, and preferably, containing metal chromium is further provided. In its production method, after the application of electrotinning on one side or both sides of the steel sheet, the steel sheet is dipped into a sodium dichromate aqueous solution. The steel sheet is further dipped into an aqueous solution of pH 2 to 3.5 containing phosphoric ions and magnesium ions, and the liquid is removed from the steel sheet. Then, the steel sheet is heated at 70 to 200 deg.C.
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