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http://dx.doi.org/10.20466/KPVP.2017.13.1.092

Evaluation of Mechanical Properties and Microstructure of Thermally Aged 308 and 316L Stainless Steel Welds  

Kong, Byeong Seo (KAIST 원자력 및 양자공학과)
Hong, Sunghoon (한수원(주) 중앙연구원)
Jang, Changheui (KAIST 원자력 및 양자공학과)
Kim, Maan-Won (한수원(주) 중앙연구원)
Publication Information
Transactions of the Korean Society of Pressure Vessels and Piping / v.13, no.1, 2017 , pp. 92-100 More about this Journal
Abstract
Due to the presence of ferrite phase in the finished welds, austenitic stainless steel welds (ASSWs) are considered susceptible to the thermal aging embrittlement during long-term service in light water reactor environment. In this study, the thermal aging embrittlement of typical ASSWs, E308 and ER316L welds, were evaluated after the long-term exposure up to 20,000 h at $400^{\circ}C$, which is considered as an accelerated thermal aging condition. After thermal aging, the decrease of tensile ductility and fracture toughness was observed. The microstructure observation with high resolution transmission electron microscopy revealed that spinodal decomposition in ferrite phase of both E308 and ER316L welds would be the main cause of the degradation of mechanical properties. Also, it was shown that the difference of thermal ageing embrittlement between ER316L and E308 welds was significant, such that the reduction of fracture resistance for ER316L weld was much larger than that of E308 weld.
Keywords
Austenitic Stainless Steel Welds; Thermal Aging; J-R curve;
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