Description / Abstract:
Purpose
This specification covers the requirements for electrodeposited
chromium plating.
Application
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.
Restriction
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
4.2.3.1 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
Safety-Hazardous Materials
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.
Classification
Classes
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.
Appearance
Class 1 plating shall have one of the following types of
lusters, as specified.
Type I - Bright finish
Type II - Satin finish.