Effect of reduced ambient pressure on weld formability, microstructure and corrosion behaviors in laser beam welding of zirconium alloy

Lianfeng Wei; Yumo Jiang; Di Xie; Yong Zheng; Shengkui Zhang; Peicheng Lin; Meng Jiang; Xi Chen; Peng He; Yanbin Chen

doi:10.1016/j.jmrt.2025.05.138

Journal of Materials Research and Technology (May 2025)

Effect of reduced ambient pressure on weld formability, microstructure and corrosion behaviors in laser beam welding of zirconium alloy

Lianfeng Wei,
Yumo Jiang,
Di Xie,
Yong Zheng,
Shengkui Zhang,
Peicheng Lin,
Meng Jiang,
Xi Chen,
Peng He,
Yanbin Chen

Affiliations

Lianfeng Wei: State Key Laboratory of Precision Welding & Joining of Materials and Structures, Harbin Institute of Technology, Harbin, 150001, China; National Key Laboratory for Science and Technology on Reactor and Materials, Nuclear Power Institute of China, Chengdu, 610041, China
Yumo Jiang: State Key Laboratory of Precision Welding & Joining of Materials and Structures, Harbin Institute of Technology, Harbin, 150001, China
Di Xie: National Key Laboratory for Science and Technology on Reactor and Materials, Nuclear Power Institute of China, Chengdu, 610041, China
Yong Zheng: National Key Laboratory for Science and Technology on Reactor and Materials, Nuclear Power Institute of China, Chengdu, 610041, China
Shengkui Zhang: State Key Laboratory of Precision Welding & Joining of Materials and Structures, Harbin Institute of Technology, Harbin, 150001, China
Peicheng Lin: State Key Laboratory of Precision Welding & Joining of Materials and Structures, Harbin Institute of Technology, Harbin, 150001, China
Meng Jiang: State Key Laboratory of Precision Welding & Joining of Materials and Structures, Harbin Institute of Technology, Harbin, 150001, China; Suzhou Research Institute, Harbin Institute of Technology, Suzhou, 215128, China; Corresponding author. State Key Laboratory of Precision Welding & Joining of Materials and Structures, Harbin Institute of Technology, Harbin, 150001, China.
Xi Chen: State Key Laboratory of Precision Welding & Joining of Materials and Structures, Harbin Institute of Technology, Harbin, 150001, China; Zhengzhou Research Institute, Harbin Institute of Technology, Zhengzhou, 450046, China; Corresponding author. State Key Laboratory of Precision Welding & Joining of Materials and Structures, Harbin Institute of Technology, Harbin, 150001, China.
Peng He: State Key Laboratory of Precision Welding & Joining of Materials and Structures, Harbin Institute of Technology, Harbin, 150001, China
Yanbin Chen: State Key Laboratory of Precision Welding & Joining of Materials and Structures, Harbin Institute of Technology, Harbin, 150001, China; Zhengzhou Research Institute, Harbin Institute of Technology, Zhengzhou, 450046, China

DOI: https://doi.org/10.1016/j.jmrt.2025.05.138
Journal volume & issue: Vol. 36
pp. 9369 – 9377

Abstract

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Welding zirconium alloys is a critical challenge in the nuclear industry owing to their high sensitivity to hydrogen and oxygen at high temperatures. This study explored the feasibility of vacuum laser welding as an alternative to conventional electron beam welding. The effects of reduced ambient pressure on weld formability, microstructure, and corrosion behavior were investigated. The results indicated a significant increase in the weld penetration depth and aspect ratio as the ambient pressure decreased from 101 kPa to 0.1 kPa. Low-vacuum conditions produced sound welds with improved surface quality and high aspect ratios. The molten pool and keyhole behaviors at different ambient pressures were experimentally and theoretically studied. The results revealed that a reduced ambient pressure transformed the welding process from thermal conductivity welding to deep keyhole welding. A larger molten pool and stable keyhole were observed in low vacuum, whereas atmospheric conditions resulted in a smaller molten pool obscured by bright plasma plumes. Microstructural analysis of welds under atmospheric and low-vacuum conditions revealed the growth of columnar crystals from both sides toward the center. Moreover, larger equiaxed crystals were observed in vacuum-welded joints owing to prolonged exposure to high temperatures, resulting from the increased heat input under low-vacuum conditions. A high-temperature, high-pressure corrosion test demonstrated that oxide film thickness gradually decreased with decreasing environmental pressure. The weld produced at 0.1 kPa exhibited excellent corrosion resistance, forming a black oxide film with good adhesion. This oxide film enhances the corrosion resistance of the weld, making it suitable for nuclear applications.

Published in Journal of Materials Research and Technology

ISSN: 2238-7854 (Print); 2214-0697 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Technology: Mining engineering. Metallurgy
Website: https://www.journals.elsevier.com/journal-of-materials-research-and-technology/

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