高耐蚀性三价铬黑铬镀层制备工艺

Process for preparation of highly corrosion-resistant black chromium coatings in trivalent chromium electrolyte

介绍了一种高耐蚀性三价铬黑铬镀层电镀工艺,包括在金属基体(如钢铁和锌合金)上制备预镀铜层、中间镀铜层、光亮镀铜层、镀镍层、高耐蚀性三价铬白铬镀层和三价铬黑铬镀层。这种三价铬复合镀层可耐中性盐雾试验96 h(无白锈),比普通三价铬黑铬镀层长一倍。

A process for preparing highly corrosion-resistant black chromium coatings on metal substrate such as iron,steels,and zinc alloys in a trivalent chromium electrolyte,was introduced,including the copper pre-electroplating,intermediate copper electroplating,bright copper electroplating,nickel electroplating,highly corrosion-resistant white trivalent chromium electroplating,and black trivalent chromium electroplating.The trivalent chromium composite coating can endure 96 hours of neutral salt spray test without the formation of white corrosion product on its surface,which is twice as long as that of a common trivalent black chromium coating.