Keyhole process in K-TIG welding on 4Â mm thick 304 stainless steel

Experiments were carried out on 4 mm thick 304 stainless steel to evaluate the keyhole behaviour in keyhole mode Tungsten Inert Gas (K-TIG). Based on the vision system, keyhole exit dimensional and positional parameters were measured from the keyhole exit image sequence. K-TIG had very narrow parameters window to get stable keyhole process in the constant parameters keyhole welding process. “One pulse one open keyhole” K-TIG welding process was achieved with square waveform pulse welding current. Stable welding process and acceptable quality welds were obtained with a relatively lower average welding current. Pulse keyhole process is feasible to improve the process window to achieve stable welding process to obtain qualified weld in K-TIG.