| 摘要 |
PURPOSE:To enhance the corrosion preventing effect of a plated layer formed on a product by mechanical plating by immersing the product in a specified chromating soln. so as to sufficiently chromate even the insides of the micropores in the plated layer. CONSTITUTION:A product coated with a film of a corrosion preventing metal by mechanical plating is immersed in a chromating soln. consisting of water, a sexivalent chromium compd. and an alcohol penetrant. Through the film formed by the mechanical plating has micropores, even the insides of the micropores can be sufficiently chromated and the corrosion resistance of the film can be improved. The corrosion preventing metal is Zn, Al, a Zn-Al alloy or mixture, an alloy or mixture of Zn and/or Al with Sn. Chromic anhydride, chromate, dichromate or a mixture of two or more kinds of such compds. is desirably used as the sexivalent chromium compd. Tert, butanol is preferably used as the alcohol penetrant.
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