| 摘要 |
PURPOSE:To obtain a steel sheet having a pure Sn layer formed discontinuously on an Ni-Sn-Fe alloy layer by plating the surface of a steel sheet with Ni, electrolytically thinning it by a specified extent of deposition, immersing the steel sheet in hot water at once, carrying out spray washing and subjecting the steel sheet to reflow treatment and chemical conversion treatment. CONSTITUTION:The surface of a steel sheet is plated with Ni, and Sn is deposited by electrolytic tinning by 0.66-1.12g/m<2>. Immediately after the tinning, the steel sheet is immersed in hot water and spray washing is carried out. The steel sheet is then subjected to reflow treatment and chemical conversion treatment. Thus, a surface treated steel sheet for a welded can having a pure Sn layer formed discontinuously on an Ni-Sn-Fe alloy layer is produced at >=300m.p.m. line speed.
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