TIN-PLATED STEEL SHEET SUPERIOR IN ADHESIVENESS OF PAINT FILM AFTER RETORT TREATMENT, AND MANUFACTURING METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a tin-plated steel sheet superior in the adhesiveness of a paint film after retort treatment and also after the elapse of time. Ž

SOLUTION: The tin-plated steel sheet has a plated tin film with a coating weight of 1.2 g/m2or more at least on the side to become the inner face of a can, and a chemical conversion coating formed on the surface of the plated tin film by cathodic electrolysis in an aqueous solution of sodium bichromate after reflow treatment. The coating weight of the chemical conversion coating is 3-8 mg/m2in terms of chromium. Furthermore, the ratio of bivalent Sn atoms with respect to all Sn atoms in the surface of the plated tin film is 35% or more but less than 75%; the ratio of quadrivalent Sn atoms is less than 50%; and the ratio of zero-valent Sn atoms is less than 30%. The method for manufacturing the same is also provided. Ž

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