Effects of gamma-ray irradiation on crevice corrosion repassivation potential of stainless steel in high temperature diluted simulated seawater |
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Authors: | Masahiko Tachibana Kazushige Ishida Yoichi Wada Nobuyuki Ota Naoto Shigenaka |
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Affiliation: | 1. Research and Development Group, Hitachi, Ltd., 7-2-1, Omika-cho, Hitachi-shi, Ibaraki 319-1221, Japan;2. Hitachi-GE Nuclear Energy, Ltd., 3-1-1 Saiwai-cho, Hitachi-shi, Ibaraki 317-0073, Japan |
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Abstract: | The crevice corrosion repassivation potentials (ER,CREV) of type 304 stainless steel (304 SS) were measured in high temperature (373–553 K), diluted simulated seawater under gamma-ray irradiation, in order to confirm the effects of gamma-ray irradiation on the crevice corrosion behavior of a representative stainless steel in seawater. Overall, for high temperatures, the ER,CREV values decreased with increasing chloride ion concentration, which was the same as the behavior observed under the non-irradiated condition. The ER,CREV values measured under gamma-ray irradiation were the same or slightly higher than ER,CREV values measured under the non-irradiated condition when the [Cl?] was the same. Consequently, it was confirmed that the threshold potential of crevice corrosion of 304 SS for the gamma-ray irradiation of 1.8 kGy at least did not deteriorate compared with the non-irradiated condition. Under the conditions of this work (seawater composition, [Cl?] range, dose rate, absorbed dose, flow rate, etc.), the crevice corrosion of 304 SS could be suppressed by maintaining the potential below the threshold potential which was determined approximately as ?0.3 V vs. SHE even for the irradiated condition at temperatures up to 553 K. |
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Keywords: | crevice corrosion seawater stainless steel high temperature gamma ray |
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