照射影響を考慮したSCC評価手法の高度化に関する研究,3; 線照射下でのステンレス鋼に形成する皮膜に対する材料と溶存酸素の影響

Research for the improvement of SCC evaluation method including the effect of radiation on water, 3; Influence of materials and dissolved oxygen related to oxide film structures on stainless steel under -ray irradiation in high temperature water

山本 正弘 ; 中原 由紀夫 ; 加藤 千明   ; 塚田 隆 ; 鈴木 和博; 畠山 祐一; 渡辺 敦志*; 布施 元正*

Yamamoto, Masahiro; Nakahara, Yukio; Kato, Chiaki; Tsukada, Takashi; Suzuki, Kazuhiro; Hatakeyama, Yuichi; Watanabe, Atsushi*; Fuse, Motomasa*

軽水炉などでは、水の放射線分解によりHO等の酸化剤が生成する。これらは材料のECPを貴な電位とし、ステンレス鋼表面に生成する腐食生成物の形態を変化させる。今回、高温高圧水中におけるSUS316LとSUS304L鋼に関して、線照射と溶存酸素が及ぼす酸化皮膜の変化をレーザラマン及びTEM分析により評価した。また、すき間部等の構造的な影響も合わせて検討した。

It is well known that the decomposition of water by irradiation results in the formation of oxidants, such as hydrogen peroxide (HO) and radical species. The oxidant such as HO promote nobler electrochemical corrosion potential (ECP) of stainless steels (SSs) and change oxide instructors as corrosion products on stainless steels surface. In this work, the effects of -ray irradiation and structure on the corrosion of Type 316L SS and 304L SS in high-temperature water of 288C were examined. We also consider structures of the oxide film on the stainless steel using transmission electron microscope (TEM) and Raman spectroscope in order to show the differences made by the irradiation and structure. In addition, the effect of diffusion restriction and surface reactions may become more significant Inside crevices, so that the environments are expected to be different from those in the outsides.