Post-irradiation annealing effects on hardness and intergranular corrosion in type 304 stainless steel
- Tokyo Electric Power Co. Inc., Yokohama (Japan). Materials Engineering Dept.
- Nippon Nuclear Fuel Development Co., Ltd., Ibaraki (Japan)
- Toshiba Corp., Yokohama (Japan). Nuclear Engineering Lab.
- Hitachi Ltd., Ibaraki (Japan). Hitachi Research Lab.
The effects of post-irradiation annealing on hardness and grain boundary corrosion were investigated on stainless steel irradiated to 1.2 {times} 10{sup 26}n/m{sup 2}(E > 1 MeV). A commercial purity type 304 steel sample was annealed at temperatures between 673K and 1,323K for terms between 300s and 360ks. Only a slight decrease in hardness was observed by annealing at 723K for 3.6ks, while significant recovery was observed at 923K and above. This dependence on annealing temperature reflected recovery in damage microstructures. Annealing at all temperatures resulted in improved corrosion resistance when evaluated by the HNO{sub 3}/Cr{sup 6+} test. In the oxalic acid test, Strauss test and double loop electrochemical potentiokinetic reactivation test, no significant change from as-irradiated material occurred at 723K and below regarding intergranular corrosion while at 773K to 923K, thermal sensitization was observed and the reactivation ratio was larger than in unirradiated material. Annealing at 1,173K led to the irradiation induced degradation in corrosion resistance being recovered to almost the same level as that in unirradiated material. Helium bubble formation was observed after annealing at 923K and above, however, no brittle grain boundary failure occurred through all the test procedures including post-annealing straining.
- OSTI ID:
- 203772
- Report Number(s):
- CONF-950816--; ISBN 1-877914-95-9
- Country of Publication:
- United States
- Language:
- English
Similar Records
The effect of ion irradiation on inert gas bubble mobility
Effect of prior cold work on intergranular and transgranular corrosion in type 304 stainless steels: Quantitative discrimination by image analysis