This specification covers the requirements for electrodeposited chromium plating.
This plating has been used typically as a decorative finish, to improve corrosion resistance, to increase wear resistance, to extend tool and die life, to maintain accuracy of gauges, and to recondition worn or undersized parts, but usage is not limited to such applications. While this document is primarily intended to address electrodeposition on steels, the process has been performed on aluminum, heat resistant alloys, high nickel alloys, super alloys, and other metals. The requirements of this specification are equivalent to AMS-QQ-320 but generally more stringent than AMS2406A. Thin Dense Chrome plating should be specified by reference to AMS2438.
Application of chromium plating to steel parts having a hardness of 48 HRC (ultimate tensile strength of 238 ksi [1641 MPa]) or higher shall not be performed unless authorized by the design documentation of the cognizant engineering organization. (See 188.8.131.52 and 8.4.2.) Application of chromium plating for repair of steel parts having a hardness of 48 HRC(ultimate tensile strength of 238 ksi (1641 Mpa) or higher requires a special design evaluation and shall not be performed unless specific approval has been received from the cognizant engineering organization
While the materials, methods, applications and processes described or referenced in this specification may involve the use of hazardous materials, this specification does not address the hazards which may be involved in such use. It is the responsibility of the user to ensure familiarity with the safe and proper use of any hazardous materials, to take precautionary measures to ensure the health and safety of all personnel involved.
Electrodeposited chromium plating shall be one of the following classes.
Class 1 - Corrosion protective plating. See 8.4.3.
Class 2 - Engineering plating. See 8.4.4.
Class 1 plating shall have one of the following types of lusters, as specified.