BS 7371-4-1994 金属紧固件涂层.第4部分:电镀镍,镍/铬和铜/镍/铬涂层规范

标准号：BS 7371-4-1994
中文标准名称：金属紧固件涂层.第4部分:电镀镍,镍/铬和铜/镍/铬涂层规范
英文标准名称：Coatings on metal fasteners - Specification for electroplated nickel, nickel/chromium and copper/nickel/chromium coatings
标准类型：A29
发布日期：1994/6/15 12:00:00
实施日期：1994/6/15 12:00:00
中国标准分类号：A29
国际标准分类号：21.060.01;25.220.40
适用范围：This Part of BS 7371 specifies requirements for coatings applied by the electrolysis of solutions of copper, nickel or chromium. The coatings consist principally of copper, nickel or chromium and are not usually lubricated. . The corrosion resistance for higher grade coatings can be improved by using two layer (duplex) nickel coatings or special types of chromium deposit. NOTE 2. The surface smoothness and brightness of the substrate will influence the appearance and corrosion protection after plating. In addition to the requirements in this Part of BS 7371, the requirements in Part 1 of the standard which are applicable to copper, nickel and chromium electroplated coatings apply. This Part of BS 7371 also specifies requirements for the following: a) the coating thickness of component metals in the coating; b) the type and thickness of chromium coating to be applied, if required; c) quality assessment of the corrosion resistance of unused coated parts when subjected to neutral salt spray testing or copper acetic salt spray testing (see for example BS 7479 : 1991); d) adhesion test. Annexes include tables indicating suitable coating grades for standard screw threads and methods of determination of coating thickness.