Advances in techniques for determination of susceptibility of welds to stress corrosion cracking (K_ISCC)

Stress corrosion cracking (SCC) is a dangerous form of environment assisted degradation. Threshold stress intensity factor for SCC (K_ISCC), an important parameter in design and prediction of life of component, is a stress intensity limit below which any crack can not propagate in corrosive environment. Accurate determination of K_ISCC is vital for predicting life of a component. Welded components often suffer from SCC in the heat affected zone (HAZ). Determination of K_ISCC of narrow HAZ of actual welds is difficult with conventional techniques. Cracks in the specimens for these techniques can propagate out of HAZ plane. This paper describes a new simple, relatively fast, and inexpensive fracture mechanics-based technique (named circumferential notch tensile (CNT) technique), and its use in testing welded specimens.