Microstructures and Mechanical Properties of 304 Stainless Steel Joints by Focused Ultrasound-Assisted TIG Welding

• Published in: Metallography, microstructure, and analysis microstructure, and analysis, 2022-02, Vol.11 (1), p.141-149
• Main Authors: Yang, Qingfu, Xu, Wanghui, Xiao, Yifeng, Xie, Weifeng, Xiong, Jinye, Zhang, Tian
• Format: Article
• Language: English
• Subjects: Austenitic stainless steels; Characterization and Evaluation of Materials; Chemistry and Materials Science; Elongation; Ferrite; Gas tungsten arc welding; Grain size; Materials Science; Mechanical properties; Metallic Materials; Microstructure; Nanotechnology; Peer Reviewed; Stainless steel; Structural Materials; Surfaces and Interfaces; Tensile strength; Thin Films; Ultrasonic imaging; Welded joints; Welding
• ISSN: 2192-9262; 2192-9270
• DOI: 10.1007/s13632-022-00826-1

The microstructure and mechanical properties of focused ultrasound-assisted TIG welds on 304 stainless steel were investigated. Compared with TIG welding, the weld depth and depth-to-width ratio of focused ultrasound-assisted TIG welding were increased by 200 and 256%, respectively. The microstructures of the focused ultrasound-assisted TIG weld were composed of austenite (98.3%) and ferrite (1.7%), and the ferrite content was higher than that of TIG welding (0.7%). The average grain size of focused ultrasound-assisted TIG weld was 32.8% smaller than that of TIG. The tensile strength and elongation of the focused ultrasound-assisted TIG joint were 764.3±18.1MPa and 66.3±3.4%, respectively, which were higher than the tensile strength (729.3±6.8MPa) and elongation (60.3±1.2%) of TIG welding. Due to the compression of arc and the stirring of the molten pool by focused ultrasound, the efficiency and penetration of focused ultrasound-assisted TIG welding were improved. The grains were refined, and the mechanical properties of joints were improved.