FRICTION STIR WELDING AND PRELIMINARY CHARACTERIZATION OF IRRADIATED 304 STAINLESS STEEL

Conference · Mon Jul 01 00:00:00 EDT 2019

DOI:https://doi.org/10.1115/PVP2019-93899· OSTI ID:1559688

Tang, Wei  ^[1]; Gussev, Maxim N.  ^[1]; Feng, Zhili  ^[1]; Gibson, Brian  ^[1]; Miller, Roger G.  ^[1]; Chen, Jian  ^[1]; Clark, Scarlett ^[1]; Leonard, Keith  ^[1]; Tatman, Jonanthan ^[2]; Sutton, Benjamin ^[2]; Frederic, Greg ^[2]

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1. ORNL
2. Electric Power Research Institute (EPRI)

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.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1559688
• Resource Relation: Conference: ASME Pressure Vessels and Piping Conference (ASME PVP 2019) - San Antonio, Texas, United States of America - 7/14/2019 12:00:00 PM-7/19/2019 12:00:00 PM
• Country of Publication: United States
• Language: English