Abstract
The mitigation of helium induced cracking in the heat affected zone (HAZ), a transition metallurgical zone between the weld zone and base metal, during repair welding is a great challenge in nuclear industry. Successful traditional fusion welding repairs are limited to metals with a maximum of a couple of atomic parts per million (appm) helium, and structural materials helium levels in operating nuclear power plants are generally exceed a couple of appm after years of operations. Therefore, fusion welding is very limited in nuclear power plants structural materials repairing. Friction stir welding (FSW) is a solid-state joining technology that reduces the drivers (temperature and tensile residual stress) for helium-induced cracking. This paper will detail initial procedural development of FSW weld trials on irradiated 304L stainless steel (304L SS) coupons utilizing a unique welding facility located at one of Oak Ridge National Laboratory's hot cell facilities. The successful early results of FSW of an irradiated 304L SS coupon containing high helium are discussed. Helium induced cracking was not observed by scanning electron microscopy in the friction stir weld zone and the metallurgical zones between the weld zone and base metal, i.e. thermal mechanical affected zone (TMAZ) and HAZ. Characterization of the weld, TMAZ and HAZ regions are detailed in this paper.
| Original language | English |
|---|---|
| Title of host publication | Codes and Standards |
| Publisher | American Society of Mechanical Engineers (ASME) |
| ISBN (Electronic) | 9780791858929 |
| DOIs | |
| State | Published - 2019 |
| Event | ASME 2019 Pressure Vessels and Piping Conference, PVP 2019 - San Antonio, United States Duration: Jul 14 2019 → Jul 19 2019 |
Publication series
| Name | American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP |
|---|---|
| Volume | 1 |
| ISSN (Print) | 0277-027X |
Conference
| Conference | ASME 2019 Pressure Vessels and Piping Conference, PVP 2019 |
|---|---|
| Country/Territory | United States |
| City | San Antonio |
| Period | 07/14/19 → 07/19/19 |
Funding
The authors gratefully acknowledge ORNL facilities and operations contributions of Allen Smith, Kathryn Kinney, C. Scott White, Chad Crawford, Mark Delph, Clay Morris, Tony Davis, Rick Bowman, Scott Thurman and numerous technical personnel from REDC and IMET of ORNL, the engineering support of Kurt Smith and Bob Sitterson, microstructure characterization efforts of Joshua Schmidlin, Xunxiang Hu, Linda Hulsey, Patricia Tedder, Travis Dixon and Brian Eckhart from LAMDA at ORNL, along with the contributions of Alan Frederick and Doug Kyle from the Processing and Joining Group of ORNL, as well as numerous technical personnel at the Electric Power Research Institute. This project is funded jointly by the U.S. Department of Energy, Office of Nuclear Energy, Light Water Reactor Sustainability Program, the Electric Power Research Institute, Long Term Operations Program, and the Welding and Repair Technology Center, with additional support from Oak Ridge National Laboratory. 1 Contact author: [email protected] This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan This project is funded jointly by the U.S. Department of Energy, Office of Nuclear Energy, Light Water Reactor Sustainability Program, the Electric Power Research Institute, Long Term Operations Program, and the Welding and Repair Technology Center, with additional support from Oak Ridge National Laboratory.
Keywords
- 304 stainless steel
- Friction Stir Welding
- Irradiated material
- Welding repair
