| 摘要 |
PROBLEM TO BE SOLVED: To provide a low-cost corrosion resistant rolling member having corrosion resistance against hydrofluoric acid by a method wherein the rolling member is one made of a metal and at least an electrolytic preservation-treated film formed of a chrome oxide is formed on the surface thereof. SOLUTION: An electrolytic preservation-treated film formed on a corrosion resisting rolling member is formed such that a corrosion resisting rolling member being a substrate to be treated is immersed in a solution containing sexivalent chrome ion, the corrosion resisting rolling member forms a cathode and a platinum or carbon forms an opposite electrode, and trivalent chrome oxide layer is formed on the surface of a substance to be treated through electrolysis utilizing oxidation reduction reaction. In a process of reduction reaction of chrome ion, control of temperature is inevitable. A chrome oxidation number in a chrome compound depends upon an electrolytic temperature during formation of a film. Namely, an electrolytic temperature at which a trivalent chrome oxide layer is formed is suitably preferable 40 deg.C or less and further suitably preferable 25 deg.C or less. The film thickness of a chrome oxide depends upon an electrolytic temperature and an electrolytic time. A film thickness is desirably 1μm or more and more preferably 1-7μm.
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