Horizontal rotating arc narrow-gap GTAW of thick Ti–6Al–4V alloy

The horizontal welding method helps simplify assembly and construction for large cylindrical components. Nonetheless, a notable challenge arises during horizontal welding, as the molten pool tends to flow downward due to gravity. To overcome this problem, a novel horizontal rotating-arc narrow-gap G...

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Main Authors: Kan Li, Chuanbao Jia, Peidun Chen, Jiakun Hu, Zhuo Wei, Qingye Zheng, Yinggang Wang, Chuansong Wu
Format: Article
Language:English
Published: Elsevier 2025-05-01
Series:Journal of Materials Research and Technology
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Online Access:http://www.sciencedirect.com/science/article/pii/S2238785425006118
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author Kan Li
Chuanbao Jia
Peidun Chen
Jiakun Hu
Zhuo Wei
Qingye Zheng
Yinggang Wang
Chuansong Wu
author_facet Kan Li
Chuanbao Jia
Peidun Chen
Jiakun Hu
Zhuo Wei
Qingye Zheng
Yinggang Wang
Chuansong Wu
author_sort Kan Li
collection DOAJ
description The horizontal welding method helps simplify assembly and construction for large cylindrical components. Nonetheless, a notable challenge arises during horizontal welding, as the molten pool tends to flow downward due to gravity. To overcome this problem, a novel horizontal rotating-arc narrow-gap GTAW method has been implemented. The rotating arc promotes the flow of the molten metal and counteracts part of the gravity acting on the molten pool when the arc force is applied below it. This suppresses the sagging trend of the molten pool and improves weld formation, ultimately resulting in well-formed and defect-free welded joints. This innovative technique successfully welded horizontally 50 mm thick Ti–6Al–4V alloy plates. During the welding process of the dual-phase titanium alloy, the high-temperature β phase develops in the weld zone (WZ). Columnar crystals are retained with the cooling of the weld and grow epitaxially under the continuous heating and remelting of the subsequent weld. Within the columnar crystals, α′ martensite interlaces with the residual β phase and forms a basketweave structure. The proportion of low-angle grain boundaries and the average Kernel Average Misorientation values of the weld zone are lower than those of the base metal. Benefiting from the martensitic strengthening effect, the tensile strength of the WZ increased by 16.9 % compared to the base metal. The tensile properties exhibit good consistency across the full thickness of the joints. The impact toughness of the WZ is significantly improved, especially showing excellent low-temperature impact toughness at 0 °C.
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issn 2238-7854
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spelling doaj-art-553058ce8a8d488ca11ece327b78e0b82025-08-20T03:42:44ZengElsevierJournal of Materials Research and Technology2238-78542025-05-013636938110.1016/j.jmrt.2025.03.101Horizontal rotating arc narrow-gap GTAW of thick Ti–6Al–4V alloyKan Li0Chuanbao Jia1Peidun Chen2Jiakun Hu3Zhuo Wei4Qingye Zheng5Yinggang Wang6Chuansong Wu7MOE Key Lab for Liquid-Solid Structure Evolution and Materials Processing, Institute of Materials Joining, Shandong University, Jinan, 250061, China; Shandong Provincial Key Laboratory of Stainless Steel and Advanced Steel Materials, Shandong Taishan Iron and Steel Group Co., Ltd., Jinan, 271100, ChinaMOE Key Lab for Liquid-Solid Structure Evolution and Materials Processing, Institute of Materials Joining, Shandong University, Jinan, 250061, China; Shandong University-Weihai Research Institute of Industrial Technology, Weihai, 264209, China; Shandong Provincial Key Laboratory of Stainless Steel and Advanced Steel Materials, Shandong Taishan Iron and Steel Group Co., Ltd., Jinan, 271100, China; Corresponding author. Shandong Provincial Key Laboratory of Stainless Steel and Advanced Steel Materials, Shandong Taishan Iron and Steel Group Co., Ltd., Jinan, 271100, China.Shandong Provincial Key Laboratory of Stainless Steel and Advanced Steel Materials, Shandong Taishan Iron and Steel Group Co., Ltd., Jinan, 271100, ChinaQingdao Product Quality Testing Research Institute, Qingdao, 266101, ChinaMOE Key Lab for Liquid-Solid Structure Evolution and Materials Processing, Institute of Materials Joining, Shandong University, Jinan, 250061, ChinaMOE Key Lab for Liquid-Solid Structure Evolution and Materials Processing, Institute of Materials Joining, Shandong University, Jinan, 250061, ChinaMOE Key Lab for Liquid-Solid Structure Evolution and Materials Processing, Institute of Materials Joining, Shandong University, Jinan, 250061, ChinaMOE Key Lab for Liquid-Solid Structure Evolution and Materials Processing, Institute of Materials Joining, Shandong University, Jinan, 250061, China; Shandong University-Weihai Research Institute of Industrial Technology, Weihai, 264209, ChinaThe horizontal welding method helps simplify assembly and construction for large cylindrical components. Nonetheless, a notable challenge arises during horizontal welding, as the molten pool tends to flow downward due to gravity. To overcome this problem, a novel horizontal rotating-arc narrow-gap GTAW method has been implemented. The rotating arc promotes the flow of the molten metal and counteracts part of the gravity acting on the molten pool when the arc force is applied below it. This suppresses the sagging trend of the molten pool and improves weld formation, ultimately resulting in well-formed and defect-free welded joints. This innovative technique successfully welded horizontally 50 mm thick Ti–6Al–4V alloy plates. During the welding process of the dual-phase titanium alloy, the high-temperature β phase develops in the weld zone (WZ). Columnar crystals are retained with the cooling of the weld and grow epitaxially under the continuous heating and remelting of the subsequent weld. Within the columnar crystals, α′ martensite interlaces with the residual β phase and forms a basketweave structure. The proportion of low-angle grain boundaries and the average Kernel Average Misorientation values of the weld zone are lower than those of the base metal. Benefiting from the martensitic strengthening effect, the tensile strength of the WZ increased by 16.9 % compared to the base metal. The tensile properties exhibit good consistency across the full thickness of the joints. The impact toughness of the WZ is significantly improved, especially showing excellent low-temperature impact toughness at 0 °C.http://www.sciencedirect.com/science/article/pii/S2238785425006118Horizontal weldingRotating arc narrow-gap weldingTitanium alloyMicrostructure evolutionMechanical properties
spellingShingle Kan Li
Chuanbao Jia
Peidun Chen
Jiakun Hu
Zhuo Wei
Qingye Zheng
Yinggang Wang
Chuansong Wu
Horizontal rotating arc narrow-gap GTAW of thick Ti–6Al–4V alloy
Journal of Materials Research and Technology
Horizontal welding
Rotating arc narrow-gap welding
Titanium alloy
Microstructure evolution
Mechanical properties
title Horizontal rotating arc narrow-gap GTAW of thick Ti–6Al–4V alloy
title_full Horizontal rotating arc narrow-gap GTAW of thick Ti–6Al–4V alloy
title_fullStr Horizontal rotating arc narrow-gap GTAW of thick Ti–6Al–4V alloy
title_full_unstemmed Horizontal rotating arc narrow-gap GTAW of thick Ti–6Al–4V alloy
title_short Horizontal rotating arc narrow-gap GTAW of thick Ti–6Al–4V alloy
title_sort horizontal rotating arc narrow gap gtaw of thick ti 6al 4v alloy
topic Horizontal welding
Rotating arc narrow-gap welding
Titanium alloy
Microstructure evolution
Mechanical properties
url http://www.sciencedirect.com/science/article/pii/S2238785425006118
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