This standard specifies the requirements for decorative, electroplated nickel plus chromium, and copper plus nickel plus chromium coatings on iron, steel, zinc alloys, copper and copper alloys, and aluminium and aluminium alloys to provide an attractive appearance and enhanced corrosion resistance. Coating designations are specified that differ in thickness and type, and guidance is given in selecting the coating designation appropriate to the service conditions to which the coated product will be exposed.
This standard does not specify the surface condition required by the base metal prior to the coating process, and is not applicable to coatings on sheet, strip or wire in the non-fabricated form nor to threaded fasteners or coil springs.
Requirements for decorative, electroplated copper plus nickel plus chromium coatings on plastic materials are specified in GB/T 12600. Similar coatings, except for the absence of a top-coat of chromium, are specified in GB/T 9798.
GB/T 12332 and GB/T 11379 specify requirements for coatings of nickel and chromium, respectively, for engineering purposes.
2 Normative References
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies.
GB/T 3138 Terminology for Metallic Coating, Chemical Treatment and Related Process (GB/T 3138-1995, neq ISO 2079:1981)
GB/T 4955 Metallic Coatings — Measurement of Coating Thickness — X-ray Spectrometric Methods — Coulometric Method by Anodic Dissolution (GB/T 4955-1997, idt ISO 2177:1985)
GB/T 5270 Metallic Coatings on Metallic Substrates — Electrodeposited and Chemically Deposited Coatings — Review of Methods Available for Testing Adhesion (GB/T 5270-1985, eqv ISO 2819:1980)
GB/T 6461-2002 Methods for Corrosion Testing of Metallic and Other Inorganic Coatings on Metallic Substrates — Rating of Test Speciments and Manufactured Articles Subjected to Corrosion Tests (ISO 10289:1999, IDT)
GB/T 6462 Metallic and Oxide Coatings — Measurement of Coating Thickness — Microscopical Method (GB/T 6462-1986, eqv ISO 1463:1982)
GB/T 6463 Metallic and Other Inorganic Coatings — Review of Methods of Measurement of Thickness (GB/T 6463-1986, eqv ISO 3882:1986)
GB/T 6465 Metallic and Other Non-organic Coatings — Corrodkote Corrosion Test (CORR Test) (GB/T 6465-1986, eqv ISO 4541:1978)
GB/T 10125-1997 Corrosion Tests in Artificial Atmospheres — Salt Spray Tests (eqv ISO 9227:1990)
