SEDL / STP / STP962-EB / STP45299S

Screening Tests for Hydrogen Stress Cracking Susceptibility

Crumly, William R.
Senior staff engineer, Hughes Aircraft Co., Electron Dynamics Division, Torrance, CA

Pages: 5    Published: Jan 1988

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Abstract

A need for a rapid, inexpensive test method for determining K^Iscc is shown. Two test methods, focusing on hydrogen stress cracking of steel, are described: (1) a test using machined, side-grooved, Charpy specimens step-loaded and held at each step under deflection controlled conditions, and (2) a slow strain rate tension test. Examples of the use of step-load test methods are presented showing excellent correlation of results between the test methods and other test methods up to a value of K^Iscc less than 0.1 ultimate tensile strength (UTS). The utility of the test method as a screening test and inexpensive estimate for K^Iscc in steels is demonstrated. It is recommended that ASTM Subcommittee F07.04 on Hydrogen Embrittlement consider standardization of this test method. The slow strain rate tension test is also examined for the use above 0.1 UTS, and a method for analyzing the test results in terms of K^Isee is presented. Both test methods are conducted under potentiostatic control in a hydrogen-producing aqueous environment.