Proton irradiation assisted localized corrosion and stress corrosion cracking in 304 nuclear grade stainless steel in simulated primary PWR water

Ping Deng^1,2，Qunjia Peng^1,3，En-Hou Han¹，Wei Ke¹，Chen Sun⁴

1. CAS Key Laboratory of Nuclear Materials and Safety Assessment, Institute of Metal Research, Chinese Academy of Sciences2. Nuclear Power Institute of China3. Suzhou Nuclear Power Research Institute4. State Power Investment Corporation Research Institute

摘 要：Localized deformation and corrosion in irradiated 304 nuclear grade stainless steel in simulated primary water were investigated. The investigation was conducted by comparing the deformation structure, the oxide scale formed at the deformation structure, and their correlation with cracking. The results revealed that increasing the irradiation dose promoted localized corrosion at the slip step and grain boundary,which was primarily attributed to the strain concentration induced by enhanced localized deformation and depletion of Cr at grain boundary. Further, a synergic effect of the enhanced localized deformation and localized corrosion at the slip step and grain boundary caused a higher cracking susceptibility of the irradiated steel.

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