An overview on the cold wire pulsed gas metal arc welding

Abstract

The demand to join newer and higher strength materials has motivated the development of controlled arc current waveforms in order to control deposition and heat input. Controlled waveforms in pulsed gas metal arc welding (P-GMAW) where the current is pulsed result in reduced nominal heat input, distortion, and residual stresses. A method to further improve these is by cold wire pulsed gas metal arc welding (CW-P-GMAW) to enhance P-GMAW with a cold wire (non-energized) fed into the weld pool. In this work, the feasibility of the process is reported and the influence of cold wire feeding on pulse parameters for low and high background to peak current ratios (Ib/Ip) were investigated through high-speed cinematography with synchronized current and voltage sampling; as well as evaluation of cross-sections via metallography. Moreover, it appears that the cold wire diminishes the heat transferred across the heat-affected zone (HAZ) for low current ratios.