2001 年 52 巻 1 号 p. 135-136
Chromium-free conversion coating films composed of Mn (II) -silicate were studied by salt spray tests, measurements of polarization resistance and surface analysis. Corrosion resistance of the film was better than the film consisting of each own component. The top of the film was composed with mainly silicate, however, inside of the film was mixture of Mn (II) and silicate. Total amounts of Mn (II) and Si in the film were an important factor for the corrosion resistance.