Investigating the Advantages of Ultrasonic-assisted Welding Technique Applied in Underwater Wet Welding by in-situ X-ray Imaging Method

Hao Chen; Ning Guo; Kexin Xu; Cheng Liu; Guodong Wang

doi:10.3390/ma13061442

Investigating the Advantages of Ultrasonic-assisted Welding Technique Applied in Underwater Wet Welding by in-situ X-ray Imaging Method

Materials (Basel). 2020 Mar 21;13(6):1442. doi: 10.3390/ma13061442.

Authors

Hao Chen^{1

2}, Ning Guo^{1

2

3}, Kexin Xu², Cheng Liu², Guodong Wang^{1

2}

Affiliations

¹ State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China.
² Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209, China.
³ Shandong Institute of Shipbuilding Technology, Weihai 264209, China.

Abstract

In this study, the effects of ultrasonic on melt pool dynamic, microstructure, and properties of underwater wet flux-cored arc welding (FCAW) joints were investigated. Ultrasonic vibration enhanced melt flow and weld pool oscillation. Grain fragmentation caused by cavitation changed microstructure morphology and decreased microstructure size. The proportion of polygonal ferrite (PF) reduced or even disappeared. The width of grain boundary ferrite (GBF) decreased from 34 to 10 μm, and the hardness increased from 204 to 276 HV. The tensile strength of the joint increased from 545 to 610 MPa, and the impact toughness increased from 65 to 71 J/mm² due to the microstructure refinement at the optimum ultrasonic power.

Keywords: FCAW; in-situ X-ray imaging; microstructure refinement; ultrasonic-assisted; underwater wet welding.

Abstract

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