Friction Stir Welding – an Advanced Approach to Repair Nuclear Power Plant Components
- ORNL
Solid phase joining technique friction stir welding (FSW) has been shown to mitigate helium-related issues in fusion welding of irradiated steels. Here, we present detailed characterization results of the first friction stir weld of an irradiated 304L stainless steel (SS) coupon contained 5.2 atomic parts per million (appm) helium. Scanning electron microscopy (SEM) was used to characterize a cross section specimen removed from the friction stir weld. No macro helium induced crack was observed at the analyzed cross-section, and only 1 – 1.5 µm size pores were found in the stir zone (SZ) and the thermal-mechanical affected zone (TMAZ). Moreover, some minor helium aggregations (Maximum ~20 µm in length) appeared along grain boundaries inside the TMAZ. Thereafter, miniature tensile specimens were extracted from the SZ, TMAZ and heat affected zone (HAZ), and base metal (BM) and tested. All welded specimens showed high total elongations (> 60%) and strengths (> 75% BM strengths). Overall, the weld made by FSW showed much better results comparing with traditional fusion welding on irradiated SS.
- Research Organization:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1890332
- Country of Publication:
- United States
- Language:
- English
Similar Records
Microstructure and mechanical properties of friction stir weld performed on neutron-irradiated 304L steel with helium
Chloride-Induced Stress Corrosion Cracking of Friction Stir-Welded 304L Stainless Steel: Effect of Microstructure and Temperature