Mechanism of Hydrogen-related Failure II

Abstract

Following the preceding article, a theory that considers the primary role of strain-induced vacancies in hydrogen-related failure is presented. Detection of lattice defects the creation and agglomeration of which are enhanced by hydrogen is described. As a support of the theory, correlations between the mount of strain-induced vacancies and the susceptibility to hydrogen-related failure are shown with steels of different microstructures. Interaction of fatigue and delayed fracture is shown as another evidence of the theory. The role of hydrogen concentration in the failure is discussed in regard to a time-dependent alteration of defects during delayed fracture test.