Spatter reduction in gas metal arc welding of stainless steel sheets using controlled bridge transfer process

In non-pulsed gas metal arc welding (GMAW), spatter can be reduced by controlling the short circuit current to a low level just before the re-arcing. The controlled bridge transfer (CBT) process, which optimises the accuracy of predicting the re-arcing in real time in response to the metal transfer, realises stable, low spatter level. In this research, the methods for controlling short circuit transfers to minimise spatter and realise stable arcs in GMAW of stainless sheet using argon rich shielded gases are investigated. The new CBT process has been developed by applying the specific arc length estimation method that is not affected by abnormal rise in arc voltage. This process can suppress the spatter generation caused by a fluctuation in the vibratory motion of the weld pool or inaccurate prediction of the re-arcing in the succeeding short circuit/re-arcing cycle, and thereby spatter free GMAW in the short circuit transfer mode can be carried out even on stainless steels.