Characteristics of a pulsed-current, vertical-up gas metal arc weld in steel

The performance of the pulsed-current gas metal are welding (GMAW) process for vertical-up weld deposition of steel has been found to be superior over the use of the short-circuiting are GMAW process with respect to the tensi le, impact, and fatigue proper-ties of the weld joint. The microstructure: weld geometry, and mechanical properties of a pulsed-current weld joint are largely governed by the pulse parameters, and correlate well to the factor phi, defined as a summarized influence of pulse parameters such as peak cu rrent, base current, pulse-off time, and pulse frequency. The increase of p hi has been found favorable to refine the microstructure and enhance the te nsile strength, C-v toughness, and fatigue life of a weld joint. The fatigu e life of a short-circuiting are weld joint has been found to be markedly r educed due to the presence of an undercut at the weld toe and incomplete si de-wall fusion of the base material.