ISO 4969-2015 PDF

Full title and description

ISO 4969:2015 — Steel — Etching method for macroscopic examination. This International Standard gives guidance for revealing and interpreting macroscopic features of steel specimens by chemical (hot and room‑temperature) and electrolytic etching, describing reagent selection, surface preparation, etching procedures and preservation of etched specimens for metallographic inspection, quality control and failure analysis.

Abstract

ISO 4969:2015 establishes guidelines for macroscopic examination of steel using hot etching, room‑temperature etching and electrolytic etching. It explains the principle of differential dissolution to reveal segregation, porosity, decarburization, case depth and other macrostructural features, and gives practical advice on sampling, surface preparation, etchants and reporting. The standard notes limitations in detecting very fine voids and cracks by macroetching alone.

General information

• Status: Published. Confirmed current at systematic review (R2020).
• Publication date: 2015 (Edition 2 — published July 2015).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 77.040.99 — Other methods of testing of metals.
• Edition / version: Edition 2 (2015).
• Number of pages: 9 pages.

Scope

ISO 4969:2015 provides general guidance for macroscopic metallographic examination of steel by chemical etching (hot and room temperature) and electrolytic etching. It covers selection and preparation of test pieces, choice of reagents and etching parameters, practical etching procedures, desmutting/neutralization and preservation of etched specimens, and reporting of results. The standard is intended for wide application across cast, wrought and forged steel products but does not set acceptance criteria — it describes methods for revealing macrostructure rather than pass/fail limits.

Key topics and requirements

• Principle of macroetching: differential dissolution to reveal segregation, porosity, cracks, decarburization, case depth and other macroscopic features.
• Sampling and specimen preparation: guidance on sectioning, orientation and surface finish to suit the feature size being inspected.
• Reagents and etching parameters: recommended types, concentrations and temperatures for common acidic and electrolytic etchants; safety and handling considerations.
• Electrolytic etching: guidance on AC/DC variants, typical current/voltage ranges and apparatus considerations.
• Post‑etch treatment and preservation: desmutting, neutralization, brief passivation and ways to preserve macroetched surfaces for records (photography, coating).
• Reporting: essential information to record (steel grade, batch/cast number, position and orientation of section, etchant used, etching conditions and descriptive/photographic documentation).

Typical use and users

This standard is used in metallurgical laboratories, QA/QC inspection departments, foundries, steel mills, forging shops and independent testing/forensic labs. Typical users include metallurgists, materials engineers, quality and inspection personnel, failure‑analysis specialists and research staff who need consistent, reproducible macroetching procedures for evaluation, documentation and comparison of macrostructural features.

Related standards

ISO 4969:2015 replaces ISO 4969:1980 (withdrawn). It is part of a family of ISO standards on steel metallography and non‑metallic inclusion assessment (for example ISO 4967 on micrographic determination of non‑metallic inclusions). Other product‑ or process‑specific standards may reference ISO 4969 for macroetching procedure guidance while defining sampling positions and acceptance criteria.

Keywords

steel, macroetching, etching, macroscopic examination, metallography, electrolytic etching, hot etching, surface preparation, QA/QC, failure analysis.

FAQ

Q: What is this standard?

A: ISO 4969:2015 is an ISO International Standard titled "Steel — Etching method for macroscopic examination" that gives guidance on chemical and electrolytic etching techniques to reveal the macroscopic structure of steel specimens.

Q: What does it cover?

A: It covers the principle of macroetching, selection and preparation of specimens, recommended etchants and etching parameters (hot, room‑temperature and electrolytic), post‑etch treatment, preservation of etched surfaces and reporting of results. It does not specify acceptance criteria for products.

Q: Who typically uses it?

A: Metallurgists, materials engineers, QA/QC inspectors, foundry and steel‑mill inspection teams, independent testing laboratories and failure‑analysis specialists.

Q: Is it current or superseded?

A: ISO 4969:2015 (Edition 2) is the current version; it replaced ISO 4969:1980 and was confirmed during a 2020 systematic review.

Q: Is it part of a series?

A: It is part of ISO/TC 17/SC 7 work on testing methods for metals and is related to other ISO metallography/testing standards (for example ISO 4967 on inclusion assessment). It complements product‑specific standards that define sampling locations and acceptance criteria.

Q: What are the key keywords?

A: Steel, macroetching, etchants, electrolytic etching, metallography, surface preparation, macrostructure, porosity, segregation, decarburization.