1 Scope
This standard specifies the specifications and test methods of the hot dip galvanized coatings (the total content of other alloying elements shall not be more than 20) on the fabricated iron and steel articles.
This standard is not applicable to the following conditions:
a) Plates, strips, wire rods, pipes and rods produced by continuous hot dipping;
b) Hot dip galvanized products adopting particular standards;
c) Hot dip galvanized products which have additional requirements or are inconsistent with the requirements of this standard.
Note: some product standards may specify the product hot dip galvanized coatings through reference in this standard or amendment of partial articles in this standard.
This standard doesn't specify the after-treatment and additional overcoating for the hot dip galvanized products.
2 Normative References
The following provisions, through reference in this text, constitute provisions of this standard. For dated reference, all subsequent amendments to (not including the errata contents), or revisions of, any of these publications do not apply. However, parties having reached an agreement on this standard are encouraged to study whether the latest revisions of these data apply or not. For undated reference, the latest revisions apply to this standard.
GB/T 470 Zinc ingots (eqv ISO 752)
GB/T 4955 Metallic coatings--Measurement of coating thickness--Coulometric method by anodic dissolution (eqv ISO 2177)
GB/T 4956 Non-magnetic coatings on magnetic substrates--Measurement of coating thickness--Magnetic method (eqv ISO 2178)
GB/T 6462 Metallic and oxide coatings--Measurement of coating thickness--Microscopical method (eqv ISO 1463)
GB/T 9793 Metallic and other inorganic coatings-Thermal spraying-Zinc、aluminum and their alloys (eqv ISO 2063)
GB/T 12334 Metallic and other inorganic coatings--Definitions and conventions concerning the measurement of thickness (eqv ISO 2064)
GB/T 13825 Metallic coatings--Determination of the mass for hot dip galvanized coatings on ferrous materials--Gravimetric method (eqv ISO 1460)
GB/T 18253 Steel and steel products-Types of inspection data (eqv ISO 10747)
ISO 2859-1 Sampling procedure for characteristic inspection-Part 1: Lot inspection sampling plan according to the determined acceptable quality level (AQL)
ISO 2859-3 Sampling procedure of characteristic inspection-Part 3: Sampling procedure of discontinuous lots
3 Terms and Definitions
The following terms and definitions as well as the ones specified in GB /T 12334 apply to this standard.
3.1 Hot Dip Galvanizing
It is one kind of processing process and method that zinc and (or) zinc-ferrum alloy coating is formed on the surfaces of the pretreated steel or cast iron articles by immerging them into the molten zinc bath.
3.2 Hot Dip Galvanized Coating
It is the zinc and (or) zinc-ferrum alloy coating on the surfaces of the iron and steel articles acquired by the hot dip galvanizing method.
Note: it is referred to as coating in this standard.
3.3 Coating Mass
It is the total mass of the zinc and (or) zinc-ferrum alloy coating on per unit area of the steel surface (in g/m2).
3.4 Coating Thickness
