NSUF 14-481: Primary Water Stress Corrosion Cracking (PWSCC) Studies Using Multi-Dimensional Materials Characterization Technologies

Stress corrosion cracking (SCC) in high temperature water is one of the most critical unknowns for failures in light-water reactors (LWRs). Extensive studies have been conducted to understand the SCC mechanisms of structure materials (Ni-base alloys, stainless steel, carbon steels, etc.). However, the SCC mechanisms are still not currently well understood. It is believed that the local temperature, chemistry, structure, stress and deformation at the crack fronts influence the crack propagation. Validated models to relate these factors with SCC mechanisms are not available. The most recent studies by Pacific Northwest National Laboratory (PNNL) using analytical transmission electron microscopy (ATEM) and atom probe tomography (APT) reveal atomic-scale processes at crack tips that drive penetrative oxidation which is believed to influence SCC crack growth. Therefore, it is possible to understand the mechanisms using advanced materials characterization technologies focusing on the microchemistry and microstructure evolution at/near crack tips. The main goal of the proposed research is to understand the potential mechanisms that drive SCC growth in the primary water environments of pressurized water reactors (PWRs) and to identify the key factors that affect the primary water SCC (PWSCC) growth rate. The research will be performed by extensive characterization of tested-specimens from PWSCC testing systems with carefully-controlled operation conditions (water chemistry, temperature, loading) and extensive comparisons between the results of different materials and the same material in different test conditions or with different pre-treatment processes (code work and heat treatment). The following tested-alloys will be analyzed: Alloys 690, 152, 52, 52M and 52i, which will be provided by GE Global Research Center (GE-GRC). The surface and near surface microstructure and microchemistry, the oxide layer cross-section structure and chemistry, the grain boundary distribution, precipitation and chemistry, the penetrative and selective oxidation, and the vacancy distribution at crack tips and near crack fronts will be extensively analyzed using multi-dimensional materials characterization technologies including TEM, field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), electron backscattered diffraction (EBSD), and energy dispersive spectroscopy (EDS).

Tilleggsinformasjon

Felt Verdi
Awarded Institution The Ohio State University
Embargo End Date 2026-02-27
Facility Tech Lead Mukesh Bachhav
NSUF Call FY 2014 RTE 2nd Call
PI Jinsuo Zhang
Project Member Yi Xie - Virginia Polytechnic Institute and State University (https://orcid.org/0000-0002-3668-733X)
Project Member Jinsuo Zhang, Professor - Virginia Polytechnic Institute and State University (https://orcid.org/0000-0002-3412-7769)
Project Type RTE
Publication Characterization of stress corrosion cracks in Ni-based weld alloys 52, 52M and 152 grown in high-temperature water Yi Xie, Yaqiao Wu, Jinsuo Zhang Materials Characterization 112 2016-06-27 http://www.sciencedirect.com/science/article/pii/S1044580315300759
Publication Characterization of stress corrosion cracks in Ni-based weld alloys 52, 52M and 152 grown in high-temperature water Materials Characterization 112 2016-06-27 http://www.sciencedirect.com/science/article/pii/S1044580315300759
RTE Number 481