A Simple Approach to the Determination of Threshold Stress Intensity for Stress Corrosion Cracking (K _ISCC) and Crack Growth of Sensitized Austenitic Stainless Steel

This article discusses the intricacies associated with the determination of threshold stress intensity for stress corrosion cracking (K _ISCC) of narrow regions such as the sensitized microstructure of austenitic stainless steel and presents a simple approach to the accurate determination of K _ISCC of a sensitized stainless steel. K _ISCC and crack growth rates of solution-annealed and sensitized AISI 304 stainless steel in the 42 wt pct MgCl₂ environment at 427 K (154 °C) were determined using the circumferential notch tensile (CNT) technique. The results presented here validate the ability of the CNT technique to overcome some of the fundamental difficulties in determination of the K _ISCC of narrow regions, using the traditional techniques. This article also discusses the mechanistic aspects of the difference in fractographic features of the sensitized and solution-annealed stainless steels.