A Brief Study of Unconventional Variants of GMAW Welding: Parameters, Weld Bead, and Microstructures

Abstract

The GMAW (Gas Metal Arc Welding) process is an electric arc welding technique widely used around the world due to its ease of use, low equipment cost and, mainly, due to the high deposition rate, the quality of the metal of solder, which makes it versatile and susceptible to modification. Thus, variants such as CW-GMAW (Cold Wire–Gas Metal Arc Welding), DCW-GMAW (Double Cold Wire–Gas Metal Arc Welding), and HW-GMAW (Hot Wire–Gas Metal Arc Welding) emerged from the conception of small adaptations to the original process that ended up generating better and more adjusted results than GMAW. Thus, variations of some parameters will be shown and their respective effects on the weld bead geometry, dilution, penetration, deposition rate, in addition to the effects on macro and microstructure. This provides the possibility of using the variants in different types of applications in the industry in general. Where the application in narrow 4 mm chamfer has already been observed, reduction of residual stresses, increase in fatigue resistance and coatings with special alloys.