Overview
EN ISO 19598:2016 - Metallic coatings covers electroplated zinc and zinc-alloy coatings on iron or steel that are finished with Cr(VI)-free passivation. Its primary purpose is to define how these coatings are designated, the minimum corrosion resistance they must achieve in prescribed tests, and the minimum coating thicknesses required. The standard addresses both pure zinc and zinc-alloy systems containing iron or nickel (zinc/iron and zinc/nickel).
Key topics and requirements
- Scope and designations
- Zn - zinc coating (no alloying element)
- ZnFe - zinc alloy containing 0.3 % to 1.0 % iron
- ZnNi - zinc alloy containing 12 % to 16 % nickel
- Cr(VI)-free passivation
- Defines passivation types and appearance codes: An (transparent), Cn (iridescent/coloured), Fn (black).
- Requires verification of absence of hexavalent chromium (Cr(VI)).
- Post treatments
- Sealants (typically ≤ 2 µm; Cr(VI)-free organic/inorganic) and top coats (> 2 µm) to enhance corrosion resistance.
- Performance requirements
- Specifies minimum corrosion resistance to be met in accelerated tests (e.g., salt spray) and minimum coating thickness; test methods and measurement (e.g., coating thickness by X‑ray spectrometry) are referenced.
- Hydrogen embrittlement
- Addresses pretreatment/post-coating procedures to reduce hydrogen embrittlement risk for high‑strength steels.
- Testing and reporting
- Requires standardized test methods and a test report containing general information and measured results.
Applications and who uses this standard
- Electroplaters and coating process engineers - to specify and validate Cr(VI)-free zinc and zinc-alloy plating processes.
- OEMs and manufacturers of fasteners, automotive, construction and industrial components - to select appropriate zinc or zinc-alloy systems for corrosion protection.
- Corrosion engineers and materials specifiers - to compare coating systems, define performance targets, and include correct designations in procurement documents.
- Test laboratories and QA teams - to carry out thickness measurements, salt spray and other accelerated corrosion tests and document compliance.
Related standards
- ISO 3497 - coating thickness measurement (X‑ray spectrometric methods)
- ISO 9227 - salt spray corrosion testing
- ISO 3613 - conversion coating test methods
- ISO 9587 / ISO 9588 - pretreatment/post-treatment to reduce hydrogen embrittlement
- ISO 27830 - guidelines for specifying metallic and inorganic coatings
EN ISO 19598:2016 is essential when specifying electroplated zinc, zinc-nickel, or zinc-iron coatings with Cr(VI)-free treatments to ensure repeatable corrosion protection, proper designation, and standardized testing.
