ASTM G37-98 (2025) PDF

Full title and description

ASTM G37-98 — Standard Practice for Use of Mattsson's Solution of pH 7.2 to Evaluate the Stress‑Corrosion Cracking Susceptibility of Copper‑Zinc Alloys (brasses). This concise practice specifies the preparation and control of the Mattsson test solution (pH 7.2) and describes its intended use as an accelerated environment for ranking the stress‑corrosion cracking susceptibility of brass alloys and brass components.

Abstract

This practice defines the composition, preparation and control limits for Mattsson’s solution (pH 7.2) used as an accelerated stress‑corrosion cracking (SCC) test environment for copper‑zinc alloys. It is intended to provide a reproducible, accelerated ranking of relative SCC susceptibility for brasses, and it emphasizes strict environmental control and appropriate specimen selection and examination to avoid misinterpretation of corrosion‑induced mechanical failures.

General information

• Status: Valid / active practice (maintained by ASTM International; widely listed as current in standards catalogs).
• Publication date: Originally approved April 10, 1998 and published in 1998 (designation G37‑98). The document appears in later catalog listings and reapproval/maintenance records (see ASTM cataloging and distributor listings showing reissue/reapproval entries).
• Publisher: ASTM International.
• ICS / categories: Corrosion of metals; copper and copper alloys (examples: ICS 77.060, 77.120.30).
• Edition / version: Designation G37‑98 (1998 edition). Some catalogs list the practice with later reapproval or catalog year markers (examples show G37‑98(2021) or G37‑98(2025) in distributor listings).
• Number of pages: 4 pages (short practice).

Scope

This practice covers the preparation and use of Mattsson’s solution of nominal pH 7.2 as an accelerated stress‑corrosion cracking test environment specifically for brasses (copper‑zinc base alloys). It describes the variables to be controlled for reproducible testing, and it notes that the practice is recommended only for brasses — use for other copper alloys may give misleading results. The practice addresses only the environmental preparation and control; specimen configuration and methods of applying stress are referenced to other ASTM practices.

Key topics and requirements

• Definition and rationale for using Mattsson’s solution as an accelerated SCC environment for brasses.
• Required composition and preparation details for the test solution (specified reagent masses/volumes, dilution and pH control to achieve pH ≈ 7.2 with stated tolerances).
• Specified control limits for pH (pH 7.2 with permitted deviation) and solution concentrations to ensure reproducibility.
• Guidance that the practice addresses only the environment — surface preparation, specimen geometry, and stress application are to be selected according to test objectives and referenced ASTM specimen practices.
• Recommendations to use unstressed control specimens and metallographic examination to distinguish stress‑corrosion failures from general or intergranular corrosion and other mechanisms.

Typical use and users

Common users are corrosion engineers, metallurgists, materials testing laboratories, brass and copper‑alloy manufacturers, and quality/control departments that need to assess or compare the SCC susceptibility of brasses. Typical uses include comparative ranking of alloy batches, evaluation of manufacturing or heat‑treatment effects on SCC susceptibility, and laboratory qualification tests where an accelerated brass SCC environment is required.

Related standards

This practice is typically used alongside other ASTM corrosion and SCC practices and test methods, for example: Practice G30 (U‑bend SCC specimens), Practice G39/G49 (bent‑beam and direct tension specimens), Practices G35/G36/G41 (environmental aspects of SCC testing), Practice G103 and Test Method G123, and related copper‑alloy corrosion standards and specifications. Users should consult referenced specimen practices for specimen configuration and stress application.

Keywords

Mattsson’s solution, pH 7.2, stress‑corrosion cracking (SCC), brass, copper‑zinc alloys, accelerated test environment, corrosion testing, SCC susceptibility, test solution preparation.

FAQ

Q: What is this standard?

A: ASTM G37‑98 is a short ASTM practice that specifies how to prepare and control Mattsson’s solution (pH 7.2) to create an accelerated stress‑corrosion cracking environment for evaluating the SCC susceptibility of copper‑zinc alloys (brasses).

Q: What does it cover?

A: It covers only the preparation, composition and control limits for the Mattsson test solution and guidance on its intended use for ranking SCC susceptibility of brasses. It does not prescribe specimen geometry or stress‑application methods (those are covered in other referenced ASTM specimen practices).

Q: Who typically uses it?

A: Corrosion testing laboratories, metallurgists, material engineers, brass manufacturers, and quality control organizations that perform accelerated SCC screening or comparative testing on brass alloys.

Q: Is it current or superseded?

A: The practice is presented and maintained under the designation G37‑98. Catalog listings and standards distributors show it as a valid/active ASTM practice; some catalogs also list it with reapproval or catalog year markers (for example, G37‑98(2021) or G37‑98(2025) in distributor entries). Users who require the latest formal status or editorial changes should consult ASTM International directly or their authorized standards supplier for the current reapproval or revision history.

Q: Is it part of a series?

A: It is part of the broader ASTM G committee suite of corrosion and stress‑corrosion testing practices and is commonly used with related G‑series practices (for specimen preparation and SCC test techniques) and other copper‑alloy corrosion standards.

Q: What are the key keywords?

A: Mattsson’s solution, pH 7.2, brass, stress‑corrosion cracking, accelerated SCC test, copper‑zinc alloys, corrosion testing.