Effect of Reversed Austenite on the Stress Corrosion Cracking of Modified 17-4PH Stainless Steel

A study has been conducted investigating the effect of reversed austenite on the stress corrosion cracking property of a chemically modified 17-4PH with specially designed two-step tempering in a simulated geothermal environment. Two specimens with very similar 0.2% proof stress and different contents of reversed austenite were used to study the effect of reversed austenite on stress corrosion cracking (SCC). Slow strain rate testing (SSRT) with hydrogen precharged specimens and under cathodic polarization confirmed the detrimental effect of reversed austenite on hydrogen embrittlement. SSRT under anodic polarization confirmed the involvement of active path corrosion in the SCC of modified 17-4PH in a simulated geothermal environment, and showed that the effect of reversed austenite on active path corrosion was also detrimental. However, SSRT was not able to resolve the most impacted SCC property, SCC initiation, or SCC propagation.