Research Status of Arc and Keyhole of K-TIG Welding

K-TIG welding method has the advantages of deep weld penetration, low cost and high efficiency, which is used in the welding of medium plate. However, in the welding process, it is difficult to control the arc energy and keyhole stability, which is easy to cause defects such as insufficient penetration, collapse of molten pool. The latest research progress in K-TIG welding field in China and foreign countries was summarized. The technological methods for improving arc shape and energy such as applying magnetic field, laser, changing gas composition. The methods for enhancing keyhole stability such as applying flux and protective gas to the back and changing the current waveform were summarized. The future development of K-TIG welding was prospected.