The Initiation of Environmentally Assisted Cracking in Semi-Elliptical Surface Cracks

Abstract

A Criterion to predict under what conditions EAC would initiate in cracks in a high-sulfur steel in contact with low-oxygen water was recently proposed by Wire and Li (1996). This EAC initiation criterion was developed using transient analyses for the diffusion of sulfides plus experimental test results. The experiments were conducted mainly on compact tension-type specimens with initial crack depths of about 2.54mm. The present paper expands upon the work of Wire and Li by presenting results for significantly deeper initial semi-elliptical surface cracks. In addition, in one specimen, the surface crack penetrated weld-deposited cladding into the high-sulfur steel. The results for the semi-elliptical surface cracks agreed quite well with the EAC initiation criterion, and provide confirmation of the applicability of the criterion to crack configurations with more restricted access to water.