Abstract
The weldability of the neutron-irradiated Stainless Steel 304 (SS 304) materials containing estimated helium levels of 12 to 44 appm has been studied through a Collaborative Research and Development Agreement between the Canadian Nuclear Laboratories and Oak Ridge National Laboratory. The work utilizes a SS 304 component harvested from the National Research Universal reactor. Laser beam welding was used to explore suitable welding conditions and associated parameters, to determine helium concentration limits for successful welding of irradiated stainless-steels. The experimental results show that maximum fusion zone void sizes, fusion zone void quantity and total heat affected zone helium-induced crack length generally increased with increasing He levels and effective weld heat input. A proper combination of welding parameters with low effective heat input, such as, laser power, weld travel speed and wire feed speed, were shown to improve the welding quality, and potentially reduce the length and probability of the formation of grain boundary helium-induced cracking and voids of irradiated SS 304 even with He concentrations as high as about 44 appm.
| Original language | English |
|---|---|
| Article number | 154193 |
| Journal | Journal of Nuclear Materials |
| Volume | 574 |
| DOIs | |
| State | Published - Feb 2023 |
Funding
The authors would like to thank Dr. Youqing Shi from CNL for Helium measurement of the NRU irradiated SS FN cup materials. This study was funded by Atomic Energy of Canada Limited, under the auspices of the Federal Nuclear Science and Technology Program. This research was also supported in part by the US DOE, Office of Nuclear Energy, Light Water Reactor Sustainability Program under Contract DOE-AC05-00OR22725 with UT-Battelle, LLC, via ORNL, and EPRI Welding & Repair Technology Center. 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 study was funded by Atomic Energy of Canada Limited, under the auspices of the Federal Nuclear Science and Technology Program. This research was also supported in part by the US DOE, Office of Nuclear Energy, Light Water Reactor Sustainability Program under Contract DOE-AC05-00OR22725 with UT-Battelle, LLC, via ORNL, and EPRI Welding & Repair Technology Center.
Keywords
- Effective heat input
- Helium-induced cracking
- Laser welding
- Neutron-irradiated Stainless Steel 304