Critical stress for stress corrosion cracking of duplex stainless steel in sour environments

The critical stress for initiation of stress corrosion cracking (SCC) of a duplex stainless steel (DSS) in a sour environment was investigated using three stress application techniques: constant-strain constant-load, and slow strain rate testing (SSRT). The critical stresses for SCC initiation as determined by detailed observation of the alloy surface after the three tests were in good agreement when a newly proposed index (sigma(c)) was adopted to express the SSRT results combined with crack observations for each test. The effect of cold work (CW) on SCC and pitting resistance of She DSS also was studied. CW did not accelerate SCC when initiation was controlled by pitting. The critical stress for SCC initiation Increased with increasing CW and the resultant increase in yield stress.