Mathematical modeling of the dynamic behavior of gas tungsten arc weld pools

• Published in: Metallurgical and materials transactions. B, Process metallurgy and materials processing science Vol. 31; no. 6; pp. 1465 - 1473
• Main Authors: KO, Sung H, FARSON, Dave F, CHOI, Sang K, YOO, Choong D
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.12.2000; Springer Nature B.V
• Subjects: Applied sciences; Exact sciences and technology; Joining, thermal cutting: metallurgical aspects; Metals. Metallurgy; Welding; Molten pool; Welding; Theoretical study; Dynamic properties; Mathematical model; GTA welding; Modeling; Weld
• ISSN: 1073-5615; 1543-1916
• DOI: 10.1007/s11663-000-0031-1

The dynamic behavior of stationary fully penetrated gas tungsten arc weld pools was investigated through numerical simulation. The effects of arc pressure, electromagnetic force, and surface tension gradients on surface depression, convection, and temperature distribution were calculated. The top surfaces of fully penetrated pools were easily depressed since they were only supported by surface tension. Circulatory convection patterns were generated by electromagnetic forces and surface tension gradients and were significantly affected by the vertical velocity component produced by ppol oscillation. The temperature distribution in and around the pool was influenced by pool convection. During pool formation and growth, the fully penetrated molten pool sagged dramatically when the bottom pool diameter approached the top diameter. The sagged pool oscillated with higher magnitude and lower frequency than partially penetrated ro fully penetrated pools before sagging occurred. The dynamicm behavior and the amount of material lost during melt-through were affected by the pool size and the magnitude of arc pressure.