ISO 3613-2021 PDF

Full title and description

St ISO 3613-2021 — Metallic and other inorganic coatings — Chromate conversion coatings on zinc, cadmium, aluminium‑zinc alloys and zinc‑aluminium alloys — Test methods. This International Standard specifies laboratory test methods for detecting and characterizing chromate conversion (passivation) coatings on zinc, cadmium and selected aluminium‑zinc/zinc‑aluminium alloys, including checks for colourless coatings, hexavalent chromium presence, coating mass, total chromium per unit area and adhesion/quality tests.

Abstract

This document gives standardized procedures to determine: presence of colourless chromate conversion coatings; presence of hexavalent chromium in colourless and coloured coatings on zinc, cadmium, aluminium‑zinc (Al ≈55 %) and zinc‑aluminium (Al ≈5 %) alloys; total chromium per unit area (zinc, cadmium); mass per unit area of colourless and coloured coatings; satisfactory adhesion of chromate conversion coatings; and general quality assessment of chromate coatings. The methods apply to chemical and electrochemical processes and to coatings free from supplementary organic or wax films.

General information

• Status: Published.
• Publication date: May 2021 (ISO publication: 2021‑05).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 25.220.20 (Surface treatment).
• Edition / version: Edition 4 (2021).
• Number of pages: ISO edition: 11 pages. (Note: some national/adopted versions such as EN/EN‑ISO or national publications include additional front matter and translations and are reported with ~20–21 pages.)

Scope

Defines test methods for laboratory determination and assessment of chromate conversion (passivation) coatings on zinc, cadmium, aluminium‑zinc and zinc‑aluminium alloys. Methods cover identification of transparent (colourless) conversions, detection of hexavalent chromium, gravimetric determination of coating mass per unit area, measurement of total chromium per unit area, adhesion checks and general coating‑quality tests. The tests are intended for coatings produced chemically or electrochemically and for coatings without supplementary organic films.

Key topics and requirements

• Identification of presence/absence of colourless chromate conversion coatings.
• Detection and determination of hexavalent chromium in coloured and colourless coatings.
• Measurement of total chromium content per unit area on zinc and cadmium substrates.
• Determination of mass per unit area for both colourless and coloured chromate coatings (gravimetric and related methods).
• Adhesion checks and simple quality assessment procedures to evaluate coating performance.
• Applicability noted to chemical and electrochemical conversion processes and to coatings free from supplementary oils, polymers or waxes.

Typical use and users

Used by surface‑treatment and electroplating laboratories, quality/control engineers in manufacturing and automotive/OEM supply chains, materials and corrosion engineers, test laboratories certifying coatings, and standards/specification writers who reference test methods for chromate passivation systems. Regulatory bodies and procurement specifications may reference ISO 3613 for conformity checks where chromate coatings are specified.

Related standards

Commonly referenced or related standards include: ISO 3613 previous editions (ISO 3613:2010 — withdrawn by the 2021 edition), ISO 4520 (chromate conversion coatings on electroplated zinc and cadmium), ISO 2081 and ISO 2082 (electroplated zinc and cadmium coatings and their supplementary treatments), and ISO 3892 (determination of coating mass per unit area — gravimetric methods). Regional/adopted versions exist as EN ISO 3613:2021 and national adoptions.

Keywords

Chromate conversion coating; chromate passivation; zinc coatings; cadmium coatings; aluminium‑zinc alloys; zinc‑aluminium alloys; hexavalent chromium detection; coating mass per unit area; adhesion test; surface treatment; ISO 3613:2021.

FAQ

Q: What is this standard?

A: ISO 3613:2021 is an International Standard that specifies laboratory test methods for chromate conversion (passivation) coatings on zinc, cadmium and specific aluminium‑zinc/zinc‑aluminium alloys.

Q: What does it cover?

A: It covers methods to detect colourless chromate coatings, determine hexavalent chromium content in colourless and coloured coatings, measure total chromium per unit area, determine coating mass per unit area, assess adhesion and perform basic quality checks. The methods apply to coatings produced chemically or electrochemically and to coatings without supplementary organic treatments.

Q: Who typically uses it?

A: Surface‑treatment and plating laboratories, quality and materials engineers in manufacturing and supply chains (including automotive and industrial OEMs), testing bodies, and standards writers or specifiers who need standardized test procedures for chromate conversion coatings.

Q: Is it current or superseded?

A: ISO 3613:2021 is the current published edition (Edition 4, published May 2021). It supersedes and replaces ISO 3613:2010 (which is withdrawn). National and regional adoptions (for example EN ISO 3613:2021) implement the same technical content with local front matter.

Q: Is it part of a series?

A: Yes — it is one of a group of ISO standards dealing with metallic and other inorganic coatings (ISO/TC 107 work), and it is commonly used alongside related standards such as ISO 4520, ISO 2081, ISO 2082 and ISO 3892 that address coating specifications, application and mass‑per‑area determination.

Q: What are the key keywords?

A: Chromate conversion, chromate passivation, zinc, cadmium, aluminium‑zinc, zinc‑aluminium, hexavalent chromium, coating mass, adhesion, ISO 3613:2021.