양성자 조사가 316 스테인리스강의 미세조직과 표면산화 특성에 미치는 영향

• Published in: Corrosion science and technology Vol. 20; no. 3; pp. 158 - 168
• Main Authors: 임연수, Yun-soo Lim, 김동진, Dong-jin Kim, 황성식, Seong Sik Hwang, 최민재, Min Jae Choi, 조성환, Sung Whan Cho
• Format: Journal Article
• Language: Korean
• Published: 한국부식방식학회 30.06.2021
• Subjects: Austenitic 316 stainless steel; IASCC; Irradiation Defects; Proton irradiation; Surface Oxidation; 금속공학; IASCC; Irradiation Defects; Austenitic 316 stainless steel; Surface Oxidation; Proton irradiation
• ISSN: 1598-6462; 2288-6524
• DOI: 10.14773/cst.2021.20.3.158

Austenitic 316 stainless steel was irradiated with protons accelerated by an energy of 2 MeV at 360 ℃, the various defects induced by this proton irradiation were characterized with microscopic equipment. In our observations irradiation defects such as dislocations and micro-voids were clearly revealed. The typical irradiation defects observed differed according to depth, indicating the evolution of irradiation defects follows the characteristics of radiation damage profiles that depend on depth. Surface oxidation tests were conducted under the simulated primary water conditions of a pressurized water reactor (PWR) to understand the role irradiation defects play in surface oxidation behavior and also to investigate the resultant irradiation assisted stress corrosion cracking (IASCC) susceptibility that occurs after exposure to PWR primary water. We found that Cr and Fe became depleted while Ni was enriched at the grain boundary beneath the surface oxidation layer both in the non-irradiated and proton-irradiated specimens. However, the degree of Cr/Fe depletion and Ni enrichment was much higher in the proton-irradiated sample than in the non-irradiated one owing to radiation-induced segregation and the irradiation defects. The microstructural and microchemical changes induced by proton irradiation all appear to significantly increase the susceptibility of austenitic 316 stainless steel to IASCC.