Study of the Eflects of Cold Work in Heat Transfer Tubing on Stress Corrosion Cracking in High Temperature Water

Abstract

The influence of cold working on the primary water stress corrosion cracking (PWSCC) susceptibility of Alloy 600 steam generator tube was investigated. A series of SCC tests were performed in high temperature (360 degrees C) water by using capsule type specimens which have different amount of old working produced by different expanding methods, i.e. mechanical rolling, hydraulic expansion and bare tube. After exposure for a long time , the relationships between the stress corrosion cracking time and the cold working parameter (tube thickness reduction rate, residual stress, dislocation densities) were evaluated. The test results indicate that higher cold working leads to higher PWSCC susceptibility.