1 Scope
This standard specifies the specifications and test methods for hot dip galvanized coatings on fabricated iron and steel articles. After-treatment/over-coating of hot dip galvanized articles is not covered in this standard.
This standard is applicable to hot dip galvanized coatings (containing not more than 2% of other metals) on fabricated iron and steel articles (including certain castings). It is not applicable to the following:
a) sheet, wire and woven or welded mesh products that are continuously hot dip galvanized;
b) tube and pipe that are hot dip galvanized in automatic plants;
c) hot dip galvanized products (e.g. fasteners) for which specific standards exist and which might include additional requirements or requirements which are different from those of this standard.
Note: Individual product standards may incorporate this standard for the coating by quoting its number, or may incorporate it with modifications specific to the product. Different requirements may also be made for galvanized coatings on products intended to meet specific regulatory requirements.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 470 Zinc ingots (GB/T 470-2008, ISO 752:2004, MOD)
GB/T 2828.1 Sampling procedures for inspection by attributes - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection (GB/T 2828.1-2012, ISO 2859-1:1999, IDT)
GB/T 2828.2 Sampling procedures for inspection by attributes - Part 2: Sampling plans indexed by limiting quality (LQ) for isolated lot inspection (GB/T 2828.2-2008, ISO 2859-2:1985, NEQ)
GB/T 2828.3 Sampling procedures for inspection by attributes - Part 3: Skip-lot sampling procedures (GB/T 2828.3-2008, ISO 2859-3:2005, IDT)
GB/T 4956 Non-magnetic coatings on magnetic substrates - Measurement of coating thickness - Magnetic method (GB/T 4956-2003, ISO 2178:1982, IDT)
GB/T 6463 Metallic and other inorganic coatings - Review of methods of measurement of thickness (GB/T 6463-2005, ISO 3882:2003, IDT)
GB/T 12334 Metallic and other inorganic coatings - Definitions and conventions concerning the measurement of thickness (GB/T 12334-2001, idt ISO 2064:1996)
GB/T 13452.2 Paints and varnishes - Determination of film thickness (GB/T 13452.2-2008, ISO 2808:2007, IDT)
GB/T 13825 Metallic coatings - Hot dip galvanized coatings on ferrous materials - Gravimetric determination of the mass per unit area (GB/T 13825-2008, ISO 1460:1992, IDT)
GB/T 18253 Steel and steel products - Types of inspection documents (GB/T 18253-2018, ISO 10474: 2013, IDT)
ISO 3549 Zinc dust pigments for paints - Specifications and test methods
EN 1179 Zinc and zinc alloys - Primary zinc
EN 13283 Zinc and zinc alloys - Secondary zinc
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 12334 and the following apply.
3.1
hot dip galvanizing
formation of a coating of zinc and/or zinc iron alloys on iron and steel articles by dipping prepared steel or cast iron in a zinc melt
3.2
hot dip galvanized coating
coating of zinc and/or zinc iron alloys on iron and steel articles obtained by hot dip galvanizing
Note: The term “hot dip galvanized coating” is subsequently referred to as the “coating”.
3.3
coating mass
total mass of zinc and/or zinc alloys per area of iron and steel product surface, expressed in g/m2
3.4
coating thickness
total thickness of zinc and/or zinc alloys on steel and iron surface, expressed in μm
3.5
significant surface
part of the article covered or to be covered by the hot dip galvanized coating and for which the coating is essential for appearance and/or serviceability
Foreword i
1 Scope
2 Normative References
3 Terms and definitions
4 General requirements
4.1 General
4.2 Hot dip galvanizing bath
4.3 Information to be supplied by the purchaser
4.4 Safety
5 Acceptance inspection and sampling
6 Coating requirements
6.1 Appearance
6.2 Thickness
6.3 Renovation
6.4 Adhesion
6.5 Acceptance criteria
7 Certificate of compliance
Annex A (Normative) Information to be supplied
Annex B (Normative) Safety requirements
Annex C (Informative) Corrosion resistance of hot dip galvanized coatings
Annex D (Informative) Determination of thickness
Annex E (Informative) Renovation of uncoated or damaged areas
Bibliography
1 Scope
This standard specifies the specifications and test methods for hot dip galvanized coatings on fabricated iron and steel articles. After-treatment/over-coating of hot dip galvanized articles is not covered in this standard.
This standard is applicable to hot dip galvanized coatings (containing not more than 2% of other metals) on fabricated iron and steel articles (including certain castings). It is not applicable to the following:
a) sheet, wire and woven or welded mesh products that are continuously hot dip galvanized;
b) tube and pipe that are hot dip galvanized in automatic plants;
c) hot dip galvanized products (e.g. fasteners) for which specific standards exist and which might include additional requirements or requirements which are different from those of this standard.
Note: Individual product standards may incorporate this standard for the coating by quoting its number, or may incorporate it with modifications specific to the product. Different requirements may also be made for galvanized coatings on products intended to meet specific regulatory requirements.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 470 Zinc ingots (GB/T 470-2008, ISO 752:2004, MOD)
GB/T 2828.1 Sampling procedures for inspection by attributes - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection (GB/T 2828.1-2012, ISO 2859-1:1999, IDT)
GB/T 2828.2 Sampling procedures for inspection by attributes - Part 2: Sampling plans indexed by limiting quality (LQ) for isolated lot inspection (GB/T 2828.2-2008, ISO 2859-2:1985, NEQ)
GB/T 2828.3 Sampling procedures for inspection by attributes - Part 3: Skip-lot sampling procedures (GB/T 2828.3-2008, ISO 2859-3:2005, IDT)
GB/T 4956 Non-magnetic coatings on magnetic substrates - Measurement of coating thickness - Magnetic method (GB/T 4956-2003, ISO 2178:1982, IDT)
GB/T 6463 Metallic and other inorganic coatings - Review of methods of measurement of thickness (GB/T 6463-2005, ISO 3882:2003, IDT)
GB/T 12334 Metallic and other inorganic coatings - Definitions and conventions concerning the measurement of thickness (GB/T 12334-2001, idt ISO 2064:1996)
GB/T 13452.2 Paints and varnishes - Determination of film thickness (GB/T 13452.2-2008, ISO 2808:2007, IDT)
GB/T 13825 Metallic coatings - Hot dip galvanized coatings on ferrous materials - Gravimetric determination of the mass per unit area (GB/T 13825-2008, ISO 1460:1992, IDT)
GB/T 18253 Steel and steel products - Types of inspection documents (GB/T 18253-2018, ISO 10474: 2013, IDT)
ISO 3549 Zinc dust pigments for paints - Specifications and test methods
EN 1179 Zinc and zinc alloys - Primary zinc
EN 13283 Zinc and zinc alloys - Secondary zinc
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 12334 and the following apply.
3.1
hot dip galvanizing
formation of a coating of zinc and/or zinc iron alloys on iron and steel articles by dipping prepared steel or cast iron in a zinc melt
3.2
hot dip galvanized coating
coating of zinc and/or zinc iron alloys on iron and steel articles obtained by hot dip galvanizing
Note: The term “hot dip galvanized coating” is subsequently referred to as the “coating”.
3.3
coating mass
total mass of zinc and/or zinc alloys per area of iron and steel product surface, expressed in g/m2
3.4
coating thickness
total thickness of zinc and/or zinc alloys on steel and iron surface, expressed in μm
3.5
significant surface
part of the article covered or to be covered by the hot dip galvanized coating and for which the coating is essential for appearance and/or serviceability
Contents of GB/T 13912-2020
Foreword i
1 Scope
2 Normative References
3 Terms and definitions
4 General requirements
4.1 General
4.2 Hot dip galvanizing bath
4.3 Information to be supplied by the purchaser
4.4 Safety
5 Acceptance inspection and sampling
6 Coating requirements
6.1 Appearance
6.2 Thickness
6.3 Renovation
6.4 Adhesion
6.5 Acceptance criteria
7 Certificate of compliance
Annex A (Normative) Information to be supplied
Annex B (Normative) Safety requirements
Annex C (Informative) Corrosion resistance of hot dip galvanized coatings
Annex D (Informative) Determination of thickness
Annex E (Informative) Renovation of uncoated or damaged areas
Bibliography
