ISO/TC 107/SC 4 - Hot dip coatings (galvanized, etc.)

This document specifies the general properties of hot dip galvanized coatings and test methods for hot dip galvanized coatings applied by dipping fabricated iron and steel articles (including certain castings) in a zinc melt (containing not more than 2 % of other metals). This document does not apply 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 can include additional requirements or requirements which are different from those of this document. NOTE Individual product standards can incorporate this document for the galvanized coating by quoting its number, or can incorporate it with modifications specific to the product. Different requirements can also be made for galvanized coatings on products intended to meet specific regulatory requirements. This document does not apply to after-treatment or additional coating of hot dip galvanized articles.

This document specifies a method of determining the mass per unit area of hot dip galvanized coatings on ferrous materials. Since an exact knowledge of the area of the surface is essential, this document is mainly applicable to shapes whose areas are easy to determine. If, with heavy samples, the specifications of Clause 7 cannot be met, then the hot dip galvanized coating mass is determined by another method.

This document gives guidelines and recommendations for the general principles of design appropriate to articles to be hot dip galvanized after fabrication (e.g. in accordance with ISO 1461) for the corrosion protection of, for example, articles that have been manufactured in accordance with EN 1090-2. This document does not apply to hot dip galvanized coatings applied to continuous wire or sheet (e.g. to EN 10346).

ISO 14708-3:2017 provides guidelines and recommendations regarding the general principles of design that are appropriate for articles to be sherardized for corrosion protection. The protection afforded by the sherardized coating to the article will depend upon the method of application of the coating, the design of the article and the specific environment to which the article is exposed. The sherardized article can be further protected by application of additional coatings (outside the scope of this document), such as organic coatings (wet paints or powder coatings). When applied to sherardized articles, this combination of coatings is often known as a "duplex system". General guidance on this subject can be found in ISO 12944‑5 and EN 13438. The maintenance of corrosion protection in service for steel with sherardized coatings is outside the scope of this document. Specific product-related requirements (e.g. for sherardized coatings on fasteners or tubes, etc.) will take precedence over these general recommendations.

ISO 14713-1:2017 provides guidelines and recommendations regarding the general principles of design which are appropriate for articles to be zinc coated for corrosion protection and the level of corrosion resistance provided by zinc coatings applied to iron or steel articles, exposed to a variety of environments. Initial protection is covered in relation to - available standard processes, - design considerations, and - environments for use. ISO 14713-1:2017 applies to zinc coatings applied by the following processes: a) hot dip galvanized coatings (applied after fabrication); b) hot dip galvanized coatings (applied onto continuous sheet); c) sherardized coatings; d) thermal sprayed coatings; e) mechanically plated coatings; f) electrodeposited coatings. These guidelines and recommendations do not deal with the maintenance of corrosion protection in service for steel with zinc coatings. Guidance on this subject can be found in ISO 12944‑5 and ISO 12944‑8.

ISO 17668:2016 specifies minimum thickness requirements for six classes of zinc diffusion layers applied to ferrous products by the sherardizing process for the purpose of protection against corrosion and wear. ISO 17668:2016 does not specify any requirements for the surface condition (finish or roughness) of the basis material before sherardizing. Post-treatments (conversion coatings), after-treatments or organic over-coatings (Duplex) of sherardized articles are not in the scope of this International Standard. NOTE 1 For general information about post-treatments, see Annex C and Annex D. ISO 17668:2016 does not apply to sherardized products (e.g. fasteners, tubes) for which specific standards exist and which might include additional requirements or requirements which are different from those of this International Standard. NOTE 2 Individual product standards can incorporate this International Standard for the coating by quoting its number, or can incorporate it with modification specific to the product.

ISO 14713-2:2009 provides guidelines and recommendations regarding the general principles of design which are appropriate for articles to be hot dip galvanized for corrosion protection. The protection afforded by the hot dip galvanized coating to the article will depend upon the method of application of the coating, the design of the article and the specific environment to which the article is exposed. The hot dip galvanized article can be further protected by application of additional coatings (outside the scope of ISO 14713-2:2009), such as organic coatings (paints or powder coatings). When applied to hot dip galvanized articles, this combination of coatings is often known as a “duplex system”. The guidelines and recommendations in ISO 14713-2:2009 do not deal with the maintenance of corrosion protection in service for steel with hot dip galvanized coatings. Guidance on this subject can be found in ISO 12944-5. Specific product-related requirements (e.g. for hot dip galvanized coatings on tubes or fasteners, etc.) will take precedence over these general recommendations.

ISO 14713-1:2009 provides guidelines and recommendations regarding the general principles of design which are appropriate for articles to be zinc coated for corrosion protection and the level of corrosion resistance provided by zinc coatings applied to iron or steel articles, exposed to a variety of environments. Initial protection is covered in relation to available standard processes, design considerations, and environments for use. ISO 14713-1:2009 applies to zinc coatings applied by the following processes: hot dip galvanized coatings (applied after fabrication); hot dip galvanized coatings (applied onto continuous sheet); sherardized coatings; thermal sprayed coatings; mechanically plated coatings; electrodeposited coatings. These guidelines and recommendations do not deal with the maintenance of corrosion protection in service for steel with zinc coatings. Guidance on this subject can be found in ISO 12944-5 and ISO 12944-8.

ISO 14713-3:2009 provides guidelines and recommendations regarding the general principles of design that are appropriate for articles to be sherardized for corrosion protection. The protection afforded by the sherardized coating to the article will depend upon the method of application of the coating, the design of the article and the specific environment to which the article is exposed. The sherardized article can be further protected by application of additional coatings (outside the scope of ISO 14713-3:2009), such as organic coatings (wet paints or powder coatings). When applied to sherardized articles, this combination of coatings is often known as a “duplex system”. General guidance on this subject can be found in ISO 12944-5 and EN 13438. The maintenance of corrosion protection in service for steel with sherardized coatings is outside the scope of ISO 14713-3:2009. Specific product-related requirements (e.g. for sherardized coatings on fasteners or tubes, etc.) will take precedence over these general recommendations.

ISO 1461:2009 specifies the general properties of coatings and test methods for coatings applied by dipping fabricated iron and steel articles (including certain castings) in a zinc melt (containing not more than 2 % of other metals). It does not apply to the following: sheet, wire and woven or welded mesh products that are continuously hot dip galvanized; tube and pipe that are hot dip galvanized in automatic plants; 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 ISO 1461:2009. After-treatment/over-coating of hot dip galvanized articles is not covered by ISO 1461:2009.

The method is based on dissolving the coating on a surface of known area in inhibited acid and determination of the resultant loss in mass by weighing the sample before and after dissolving. Since knowledge of area of the surface is essential, it is mainly applicable to shapes whose areas are easy to determine.