Investigation into the fusion characteristics of STT MAG welding process

摘要

Surface Tension Transfer (STT) MAG welding, is a patented process from Lincoln, USA. This process has been developed to overcome the spatter and cold lapping problems associated with dip transfer welding in conventional GMAW process. STT employs wave form control technology to precisely control the current and thereby regulates the physical processes involved in short circuit transfer welding. The influence of the process parameters viz, peak current, background current, stand- off distance and wire-feed speed on the fussional characteristics have been investigated. Increasing the peak current is found to increase the penetration plate fusion and dilution. Arc stability and metal transfer is found to depend on the background current. Though the process is stable when the stand- off distance is changed within same range, large change in stand-off distance is found to affect the process stability.