METALLIC MEMBER WITH CHROMATE FILM, MANUFACTURING METHOD THEREFOR, AND SPARK PLUG

摘要

PROBLEM TO BE SOLVED: To provide a metallic member in which a chromate film containing only a little hexavalent chromium and having a good slidability is formed, a spark plug with chromate film, and provide these production methods. SOLUTION: A metallic member 55 (a galvanized layer 56 is formed for corrosion prevention) having a sliding expecting face where sliding is expected between the metallic member and another member is dipped in a chromate treating bath in which a complexing agent is mixed with a trivalent chromium salt to form 0.2-0.5μm thick film 57 in which 95 mass % or more of the containing chromium component is trivalent chromium on the expected sliding face. Thereafter, by heat-treating the chromate film 57 at 85-255 deg.C, the slidability of the chromate film 57 can be improved. As a result, the metallic member 55 with the chromate film on which a chromate film is formed becomes easily slidable against other members.