Analysis of the frequency features of arc voltage and its application to the recognition of welding penetration in K-TIG welding

摘要

Keyhole tungsten inert gas (K-TIG) welding is a novel and high-efficiency welding method and is characterized by the formed keyhole. In this paper, a multisensor sensing system is set up to collect voltage, current and arc sound signals. K-TIG experiments on Ti alloy and 304 stainless steel are carried out. A distinct frequency band at 2-4 kHz is found, and its physical significance is analyzed, which has a correlation with weld pool oscillation. The weld pool oscillation frequency is then extracted by the proposed algorithm. The oscillation modes in different weld states are analyzed, and the special mode in full penetration is determined. The difference in oscillation frequency between partial penetration and full penetration is distinct, and it is believed that the combination of the discovered frequency band and the proposed algorithm can be utilized to conveniently identify weld penetration.