Detection of Peculiar Frequency of Molten Pool and Estimation of Penetration in Pulse TIG Welding
Yasuo SUGA, Takuya TOKIWA, Kaoru YASUDA
In automatic butt welding of relatively thin plates, it is important to control welding conditions in order to obtain a sound full penetration weld. Especially, it is difficult to obtain a full penetration weld, because the optimum welding conditions change with groove conditions, such as gap of groove, shape of groove and so on. Recently, it was reported that there is an intimate relationship between the oscillation of the molten pool and penetration. The frequency of a molten pool decreases drastically with transformation from partial penetration to full penetration. Accordingly, estimation of penetration mode by detecting frequency of the molten pool is attempted.
In this study, the principle of detection of penetration, detection method of molten pool oscillation and construction of system for estimating peculiar frequency of the molten pool oscillation are investigated. As the results of welding experiments, it is shown that the system constructed is effective in detecting molten pool oscillation and estimating penetration mode during TIG arc welding of thin plates.