| 摘要 |
PROBLEM TO BE SOLVED: To provide a production method of a galvanized steel sheet having excellent outward appearance by using a high strength steel sheet as its original plate. SOLUTION: The steel sheet containing by wt. >=0.05% Si and Mn and/or Cr (the total of Si, Mn and/or Cr is >=1.5%) is dipped into a galvanizing bath containing 0.05-0.5% Al at >=440 deg.C, and at the dipped sheet temp T( deg.C) satisfying the following inequalities I and II to execute the galvanization. Further, in the above production method, on the steel sheet surface before galvanizing, pre-plating with at least one element of Ni and Co at 0.2 to 3.0 g/m2 is executed. Inequality I: 350+30/t<=T( deg.C)<=420+30/t. (wherein, (t) is the sheet thickness (mm)). Inequality II: T( deg.C)<=460.
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