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Published on: August 13, 2019
Microstructure and Impact Toughness of Local-Dry Keyhole Tungsten Inert Gas Welded Joints
Shuwan Cui1,2, Zhiyong Xian3, Yonghua Shi4,5
1School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640, China. 13597066615@163.com.
Abstract:
In this paper, the microstructure and impact toughness of a S32101 duplex stainless steel underwater local-dry keyhole tungsten inert gas welded joint were studied. The impact toughness value of the underwater weld metal reached 78% of the onshore weld metal, which is in accordance with the underwater welding standards. The proportion of austenite in the underwater weld metal was 0.9% lower than that of the onshore weld metal. The proportion of the Σ3 coincidence site lattice boundaries and random phase boundaries in the underwater weld metal, which significantly influence the impact toughness of the weld metal, were smaller than that of the onshore weld metal.
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