Ring test of 304 stainless steel tube oxidized in high temperature steam

The residual mechanical strength and ductility of 304 stainless steel claddings were studied in tests of ring compression, ring tension and hardness. The tests were made after the specimens had been heated in steam and in argon gas to temperatures between 900° C and 1350° C. The effects of crystal grain growth and oxygen absorption in the metal on the residual properties were also studied. The experiments showed that the claddings retained their ductility well at temperatures below 1300° C and when the oxide scale thickness was below 40% of the initial wall thickness. The claddings maintained a constant level of residual strength when heated at temperatures over 1000° C or when the oxide thickness was over five percent. These results were used to support our proposals for limits on stainless steel cladding damage in a LOCA.