Residual Stress Modeling and Advanced Diffraction Measurements of 347H Steel Weldments

Conference · Fri Jul 01 04:00:00 EDT 2022

DOI:https://doi.org/10.1115/PVP2022-85608· OSTI ID:2447340

Yang, Yi ^[1]; Han, Dong ^[2]; Gao, Yanfei ^[2]; Zhang, Wei ^[1]; Bunn, Jeffrey R. ^[1]; Payzant, Andrew ^[1]; Yakovenko, Andrey ^[3]; Penso, Jorge ^[4]; Feng, Zhili ^[1]

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1. ORNL
2. University of Tennessee, Knoxville (UTK)
3. Argonne National Laboratory (ANL), Advanced Photon Source (APS)
4. Shell Projects and Technology

The 347H stainless steel is a primary high-temperature material for many energy and power generation industries. Stress relief cracking (SRC) has been a particular concern in welding of this material. The residual stress induced by welding and its evolution during post-welding heat treatment (PWHT) and subsequent operating and service conditions is one of the primary factors contributing to SRC. The lifetime of welded structure components is also controlled by the precipitation kinetics that accompanies PWHT, stress relaxation process, and long-term aging and complex synergistic factors. Various theories have been proposed in the past to explain SRC. However, a widely accepted approach to predicting the entire damage evolution and the resulting performance reduction is still lacking. This study is to demonstrate a reliable solution for two critical issues that affect the predictions. First, the residual stress distribution obtained from both simulation and neutron diffraction is compared, which increases the accuracy of mechanical analysis simulation model and therefore builds a solid basis for the lifetime prediction model. Second, the generation, evolution, and annihilation of precipitates are monitored by the synchrotron diffraction experiment. Preliminary results demonstrate the critical importance of precipitation kinetics on the residual stress distribution/redistribution during heat treatments.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE; USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 2447340
• Country of Publication: United States
• Language: English