SCC OF HIGH CR ALLOYS IN BWR ENVIRONMENTS

摘要

The current generation of weld metals used in BWRs, Alloy 182 and 82, have shown significant susceptibility to SCC in the laboratory and/or the field. With the laboratory data showing less than a factor of two difference in crack growth rate between the ～15% Cr Alloy 182 and the ～20% Cr Alloy 82, it seems clear that Alloy 82 will not be sufficiently resistant for long term SCC resistance. The higher Cr weld metals, Alloy 52i and 52, have dramatically greater (>100X) resistance to SCC than the current generation of weld metals, and indeed exhibit remarkable resistance to high corrosion potential, high water impurity levels, and high stress intensity factor.