Effects of Hydrogen on the PWSCC Initiation Behaviours of Alloy 182 Weld in PWR Environments

• DOI: 10.14773/cst.2015.14.3.113
• Publication Date: 2015-08-11T20:44:28Z
• Authors: H.-S. Kim; J.-D. Hong; J. Lee; O.S. Gokul; C. Jang
• Keywords: Pressurized water reactor

Alloy 82/182 weld metals had been extensively used in joining the components of PWR primary system. Unfortunately, there have a number incidents cracking caused by PWSCC welds during operation worldwide. To mitigate PWSCC, optimization water-chemistry conditions, especially dissolved hydrogen (DH) and Zn contents, is considered as most promising effective remedial method. In this study, behaviours 182 were investigated simulated environments with various DH content. Both in-situ ex-situ oxide characterizations well initiation tests performed. The results showed that crack time was shortest water (DH: 30cc/kg). Also, high stress reduced time. Oxide layer multi-layered structures consisted outer needle-like Ni-rich layer, Fe-rich crystalline oxide, inner Cr-rich layers, which not altered level applied stress. analyse multi-layer structure oxides, EIS measurement fitted into an equivalent circuit model. Further analyses including TEM EDS are underway to verify appropriateness