| 摘要 |
PURPOSE:To form a corrosion resistant uniform layer on an Mg material by pickling the Mg material with an aqueous soln. contg. chromic acid, immersing the material in hot water and bringing it into contact with an electrochemically nobler metal in a bath for forming a film by chemical conversion treatment. CONSTITUTION:The surface of an Mg or Mg alloy material is degreased and pickled with an aqueous soln. contg. chromic anhydride or the like. The material is immersed in hot water at >=about 80 deg.C and then immersed in an aqueous soln. contg. a chromate such as sodium dichromate for forming a film by chemical conversion treatment. The material is brought into contact with an electrochemically nobler metal in the aqueous soln. to form a film by chemical conversion treatment. The formed film does not fall off and has high shelf stability for a long period.
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