| 摘要 |
PURPOSE:To develop a surface treated steel sheet for can making having excellent seam weldability and the corrosion resistance under a coated film by forming the chromate treatment layer of the steel sheet which has fine ruggedness on the surface and has an Fe-Sn alloy plating layer, Sn plating layer and chromate treatment layer to the thickness inversely proportional to the thickness of the Sn plating layer in said part. CONSTITUTION:The rugged Sn plating layer 2 which has the fine ruggedness of 1-30mum spacings in projecting parts and has <0.07mum plating thickness of recesses, >=0.20mum plating thickness of the projecting parts and <=0.17mum average plating thickness is formed on the steel sheet 4 coated with Ni or Ni alloy contg. 1 or >=2 kinds among Ni-Fe, Ni-P, Ni-Zn, Ni-Cu, and Ni-Cr alloys to form an Sn-Fe alloy layer 1 between the steel sheet and the plating layer by the inter-diffusion with the steel base. The chromate treatment film 3 is formed on such rugged Sn plating layer 2 in such a manner that the thickness thereof is inversely proportional to the thickness of the Sn plating layer 2.
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