| 摘要 |
PROBLEM TO BE SOLVED: To provide an evaluating method capable of determining whether the corrosion resistance of a tervalent chromate film is good or not even without performing a corrosion resistance test, to provide a highly corrosion resistant member with a tervalent chromate film having high corrosion resistance, and to provide its production method. SOLUTION: In the highly corrosion resistant member having: a substrate made of steel; a plating layer formed on the surface of the substrate; and a tervalent chromate film formed on the surface of the plating layer, whether the corrosion resistance of the tervalent chromate film is good or not is determined based on the value of the concentration ratio (Si/Cr) between silica and chromium in the tervalent chromate film. Further, the highly corrosion resistant member having the tervalent chromate film is composed in such a manner that the value of the concentration ratio (Si/Cr) between silica and chromium in the tervalent chromate film reaches≥0.75. COPYRIGHT: (C)2007,JPO&INPIT
|
