Stress corrosion cracking—A new approach to testing methods

Abstract

So far, the primary objectives of the investigation of stress corrosion cracking have been to understand the basic mechanisms and also to find suitable testing methods for screening materials according to their degree of susceptibility, with an aim to avoid failures caused by stress corrosion cracking in various applications and environments. Because of the complexity of interplay among various mechanical, metallurgical, and environmental factors, considerable ambiguity and debates still exist about the basic mechanisms. As a consequence, several different mechanisms were proposed to explain failures related to the interaction of metals with environments. The development of standard and practical testing methods is another area of studies on stress corrosion cracking. Although there exist some standard testing methods capable of the quantitative assessment of susceptibility to cracking, most of these methods require long durations of tests and are characterized by significant variability in their results. We discuss a new method, which has gained importance in the last few years. The applicability of this method as a standard testing procedure is checked and explained on the basis of the results obtained in testing an aluminum alloy in a chloride solution.