Stress corrosion cracking of Ti- and Nb-stabilized austenitic stainless steels in 288 C water

Intergranular stress corrosion cracking of stabilized austenitic stainless steels in 288 C water has been studied experimentally. Fracture mechanics crack growth rates were obtained with double cantilever beam specimens. Three Ti-stabilized and two Nb-stabilized stainless steels all exhibited intergranular stress corrosion cracking in simulated, faulted BWR water. The crack growth rates were similar to those of 316 NG, i.e. about one nun per year at stress intensities beyond 20 MPa√m. Extreme sensitization and coarse grains result in crack growth rates up to one hundred times faster. It is shown that weld sensitization in a very narrow zone (several hundred micrometers from the fusion line) can cause chromium carbide precipitation and corresponding chromium depletion and corresponding susceptibility to stress corrosion cracking in BWR water