ASTM B456 – Standard Specification for Electrodeposited Coatings of Copper Plus Nickel Plus Chromium and Nickel Plus Chromium
Description:
Abstract
This specification establishes the requirements for several types and grades of electrodeposited copper plus nickel plus chromium and nickel plus chromium coatings on steel, copper, copper alloys, Type 300 and 400 series stainless steels, aluminum, aluminum alloys, and zinc alloys for application where both appearance and protection of the basis metal against corrosion are important. This specification does not cover plating on plastics. Each coating shall be designated a classification code, which comprises of the following numbers and symbols: service condition number, which indicates the severity of exposure for which the coating is intended; coating classification number, which contains the chemical symbol of each metallic element that comprises the basis metal, or the designated AISI number in the case of stainless steels, and their corresponding thickness; and symbols for expressing the type of coating. Products shall be sampled and inspected accordingly for visual defects, thickness, adhesion, elongation, ductility, corrosion, sulfur content, density, and discontinuities.
Scope
1.1 This specification covers requirements for several types and grades of electrodeposited copper plus nickel plus chromium or nickel plus chromium coatings on steel, nickel plus chromium coatings on copper and copper alloys, nickel plus chromium coatings on Type 300 and 400 series stainless steel and copper plus nickel plus chromium coatings on aluminum and its alloys and zinc alloys for applications where both appearance and protection of the basis metal against corrosion are important. Five grades of coatings are provided to correspond with the service conditions under which each is expected to provide satisfactory performance: namely, extended very severe, very severe, severe, moderate, and mild. Definitions and typical examples of these service conditions are provided in Appendix X1.
1.2 This specification does not cover the requirements for the plating on plastics, see Specification B604.