Abstract: A Zn or part-Zn plated steel sheet has an MgO coating free of metallic Mg thereon which increases corrosion resistance and plating adherence. The MgO coating is formed by coating according to the sol-gel method or by dipping or treating by cathodic electrolysis a Zn or part-Zn plated steel sheet in a molten salt bath mainly containing a magnesium salt.

Abstract: A process for the manufacture of tinplates comprising electroplating a substrate in a fused-chloride tin plating bath at a temperature of about 150.degree. to 350.degree. C., a current density of about 100 to 500 A/dm.sup.2 in an atmosphere of a non-oxidizing gas. This process may be converted to a process for the manufacture of reflow type tinplates by only changing the bath temperature, and vice versa. For the manufacture of no-reflow type tinplates, the bath is kept at 150.degree. to 232.degree. C., while for the manufacture of reflow type tinplates, the bath is kept at 233.degree. to 350.degree. C. In these cases, the bath includes SnCl.sub.2 and at least one member selected from the group consisting of KCl, NaCl, LiCl and AlCl.sub.3, and may preferably be operated while flowing the bath at a flow rate of about 0.1 m/sec higher.