目前,可以用作电镀和涂敷的材料种类很多。螺栓外表的保护层究竟选用电镀还是涂敷方式,还需要从几个方面来分析。螺栓表面无论是镀镉还是镀锌,镀好后都必须在湿度很大的环境中经受96小时以上的考验。从美国材料试验标准(ASTM)中可以看到,铬酸盐与锌或镉镀层的抗腐蚀最低标准与镀层厚度、电镀方式、镀件类型都有关:(1)在镀锌层上再涂上一层铬酸盐的螺栓至少在120～216小时之内不会出现白色腐蚀 Currently, there are many types of materials that can be used for electroplating and coating. Bolt appearance of the protective layer of the choice of plating or coating method, but also from several aspects to analyze. Whether the surface of the bolt cadmium plated or galvanized, after plating must be in a very humid environment to withstand 96 hours or more of the test. According to ASTM, the minimum standard of corrosion resistance of chromate and zinc or cadmium coating is related to coating thickness, plating method and plating type. (1) Apply to zinc coating again A layer of chromate bolts will not white corrosion for at least 120 ~ 216 hours