Senior research engineer, Research Institute, Ishikawajima-Harima Heavy Industries Co., Ltd. (IHI), Tokyo,
Pages: 12 Published: Jan 1994
In order to study the effects of introducing an artificial crevice to the specimen on the stress-corrosion cracking (SCO test for stainless alloys in the boiling water reactor (BWR) primary coolant environments, uniaxial constant load tests were performed in a high-temperature, high-purity water environment on Type 304 stainless steel and Alloy 600 type Ni-base alloys, both sensitized. 0n analyzing the lifetime distribution data by fitting to the exponential distribution model, it was found: (1) the lifetime to initiation of SCC can be accelerated by introducing an artificial crevice to the specimen; (2) the acceleration efficacy of graphite-fiber wool as a crevice-forming material is confirmed; (3) the acceleration effect of artificial crevice is stronger for Alloy 600 type Ni-base alloys than the Type 304 stainless steel by a factor of 5 to 6; and (4) by comparison of the performance data in actual environments and the results of analysis conducted on the laboratory acceleration test data, the use of artificially-creviced specimen for the SCC lifetime test has been justified because it effectively shortened the SCC initiation lifetime without losing the factual correspondence to the SCC that occurs in actual service environments.
stress-corrosion cracking, stainless steel, Ni-base alloy, BWR environment, artificial crevice, lifetime distribution
Paper ID: STP24891S