Session: MF-03-01 Welding Residual Stress and Distortion Simulation and Measurement

Paper Number: 103449

103449 - Modeling of Hardness and Welding Residual Stress in Type 316 Stainless Steel Components for the Assessment of Stress Corrosion Cracking 

Intergranular stress corrosion cracking (SCC) was recently detected in austenitic stainless steel welded joints in pressurized water reactors (PWRs) in Japan and France. High tensile residual stress and hardness near the weld root, which may be induced by the welding process, are important factors that affect the SCC of austenitic stainless steel components in PWRs. In this work, we firstly proposed a framework on the comprehensive assessment of hardness and welding residual stress in Type 316 austenitic stainless steel weld joints. Firstly, an 8-pass butt-welded pipe joint made of Type 316 stainless steel was fabricated. Finite element analysis of the pipe joint was performed. The grain growth model and a time-temperature dependent annealing model were developed. The Chaboche combined isotropic-kinematic strain hardening model was adopted. The relationships between the Vickers hardness and the uniaxial plastic strain as well as grain size were determined experimentally, respectively. The simulation results of the grain size and accumulated equivalent plastic strain were used for the hardness prediction of the welded joint. The simulation results were compared with the experimental data of hardness mapping. The distributions of welding residual stress on the outer and inner surfaces were measured by using the strain gauge relief method. The predicted welding residual stresses were compared with the measurements. The results obtained have shown that the developed numerical approach can predict the hardness and welding residual stress of Type 316 stainless steel welded joints with high accuracy. Then, the possible factors influencing the hardness and welding residual stress during the manufacturing process are briefly discussed. The effects of structural constraint and heat input on the hardness and welding residual stress will be numerically investigated as further works, which will be described in the proposed framework.

Presenting Author: Suo Li Japan Atomic Energy Agency

Presenting Author Biography: Dr. Suo Li is currently a postdoctoral fellow at the Nuclear Safety Research Center of Japan Atomic Energy Agency. Following his Bachelor's degree from Huazhong University of Science and Technology, he obtained his Master's and Doctoral degrees at Chongqing University, both in Materials Science and Engineering. He was a sponsored researcher at the University of Nottingham from 2019 to 2020. His research is focused on the modeling and measurement of residual stresses in similar/dissimilar metal welds for the assessment of structural integrity of power plant components. He has published 20+ peer-reviewed journal papers.

Authors:

Suo Li Japan Atomic Energy Agency
Yoshihito Yamaguchi Japan Atomic Energy Agency
Jinya Katsuyama Japan Atomic Energy Agency
Yinsheng Li Japan Atomic Energy Agency
Dean Deng Chongqing University