Effect of Cable Length on Welding Quality in Asynchronous Tandem Gas Metal Arc Welding

When the gas metal arc welding (GMAW) process is applied in the shipbuilding and heavy equipment industries, it is important to increase the amount of welding on the weld without defects. Application of the tandem GMAW process can reduce the man-hours increased owing to multipass and increase productivity. In shipbuilding and heavy equipment industry sites, the weldments are long and large; thus, a carriage-type bed is generally used. Accordingly, the overall lengths of the welding cables in the welding system are increased; thus, arc voltage drop occurs owing to the load voltages generated in the welding cables, and a robust bead cannot be obtained owing to spatters caused by short circuits. In this study, the voltage drop caused by the increase in cable lengths was compensated using a developed welding machine. By compensating for the voltage drop, it was possible to obtain a good quality bead by reducing the occurrence of spatter caused by short circuit. As a result of performing one pass welding using the asynchronous tandem GMAW process and the developed welding machine, it was possible to secure sufficient amount of welding required in the field and to obtain a sound bead appearance.