EVALUATION OF LIQUID-METAL EMBRITTLEMENT OF STAINLESS-STEEL 304 BY CADMIUM AND CADMIUM ALUMINUM SOLUTIONS

The susceptibility of stainless steel 304 (SS304) to liquid metal embr ittlement (LME) by cadmium (Cd) and cadmium-aluminum (Cd-Al) solutions was examined as part of a failure evaluation for SS304-clad cadmium r eactor safety rods which had been exposed to elevated temperatures. Th e safety rod test data and destructive examination of the specimens in dicated that LME was not the failure mode. The available literature da ta also suggest that austenitic stainless steels are not particularly susceptible to LME by Cd or Cd-Al solutions. However, the literature d ata is not conclusive and an experimental study was therefore conducte d to examine the susceptibility of SS304 to LME by Cd and Cd-Al soluti ons. Temperatures from 325 to 600-degrees-C and strain rates from 1 X 10(-6) to 5 x 10(-5) s-1 were of interest in this evaluation. Tensile tests carried out in molten Cd-Al and Cd solutions over these temperat ures and strain rates with both smooth bar and notched specimens showe d no evidence of LME. U-bend tests conducted in liquid Cd at 500 and 6 00-degrees-C also showed no evidence of LME. It is concluded that SS30 4 is not subject to LME by Cd or Cd-Al solutions over the range of tem peratures and strain rates of interest.