ISO 2081:2018

Overview

ISO 2081:2018 - "Metallic and other inorganic coatings - Electroplated coatings of zinc with supplementary treatments on iron or steel" - specifies requirements for electroplated zinc coatings applied to iron or steel items for protective and decorative purposes. The standard covers information the purchaser must supply to the electroplater, requirements for heat treatments before and after electroplating, and criteria for appearance, thickness, adhesion and accelerated corrosion testing. ISO 2081:2018 excludes non‑fabricated sheet/strip/wire, close‑coiled springs and coatings applied for non‑protective/decorative purposes.

Key topics and technical requirements

• Scope and exclusions: Applies to electroplated zinc (acid or alkaline processes) with supplementary treatments; not applicable to sheet/strip/wire in the non‑fabricated form, close‑coiled springs or non‑protective applications.
• Purchaser information: Specifies essential information to be supplied (reference to ISO 2081, designation, significant surfaces, basis metal condition, finish, conversion/coating type, thickness and adhesion requirements, tensile strength and heat‑treatment needs, sampling/acceptance criteria).
• Designation format: Defines how to designate electroplated zinc coatings (basis metal, stress relief (SR), zinc thickness, hydrogen embrittlement relief (ER), conversion coating codes).
• Appearance and finish: Requires agreement on finish (bright, dull, etc.) and notes that basis‑metal surface defects affect coating performance.
• Coating thickness & measurement: Sets requirements for zinc coating thickness and references microscopical methods (ISO 1463) and conventions (ISO 2064) for measurement.
• Supplementary treatments: Includes trivalent chromium conversion coatings and other supplementary treatments (codes provided in Annex A); recognizes shift toward Cr(III) and Cr(VI)-free alternatives (see ISO 19598).
• Adhesion and testing: Addresses adhesion testing and accelerated corrosion testing (neutral salt spray per ISO 9227 and corrosion rating per ISO 10289).
• Hydrogen embrittlement: Specifies requirements for stress‑relief heat treatments before cleaning/deposition and hydrogen‑embrittlement‑relief heat treatments after electroplating; references ISO 9587/9588, ISO 15330 and ISO 15724.
• Sampling & inspection: Sampling procedures by attributes are referenced (ISO 4519).

Applications and who uses it

ISO 2081:2018 is used by:

• Electroplaters and surface‑finishing shops implementing specification requirements for zinc electroplating.
• Design engineers and purchasers who must specify coating designation, thickness, finish and heat‑treatment requirements on drawings and purchase orders.
• Quality and corrosion engineers responsible for testing (salt spray, adhesion, hydrogen embrittlement) and acceptance criteria.
• Manufacturers of fasteners, automotive components, construction parts and other steel/iron articles requiring corrosion protection and decorative zinc plating.

Related standards (selection)

• ISO 1463 - coating thickness measurement (microscopical method)
• ISO 9227 - neutral salt spray corrosion testing
• ISO 19598 - Cr(III)-only conversion coatings for zinc/zinc-alloy platings
• ISO 4519 - sampling procedures for electrodeposited coatings
• ISO 9587 / ISO 9588, ISO 15330 - hydrogen embrittlement prevention and testing

Keywords: ISO 2081:2018, electroplated zinc, zinc coatings, trivalent chromium, corrosion resistance, coating thickness, hydrogen embrittlement, neutral salt spray, electroplater.