**4. Conclusions**

Modifications of the GMAW process giving rise to the CW-GMAW, DCW-GMAW, and HW-GMAW variants provide very significant results, despite a very similar trend when the percentages of extra wire become very high from 80%, regardless of whether this extra wire is energized or not. However, some observations must be addressed:

1.The CW-GMAW variant in several works presents greater versatility of implementation and use in different sectors of the industry, both for straight and narrow gap and for angled chamfers, in addition to the possibility of application for coatings, whether special or not. In general, low electrode wire feed speeds and low percentages of extra wire favor the variant in use for splices, as linear penetration remains almost unchanged. However, high wire feed speeds and high percentages of cold wire allow for a decrease in penetration, dilution, and w/h ratio, increasing the height of the reinforcement, favoring its use for coatings. This feasibility is further increased when the combination of wires used can be manipulated, generating different chemical combinations for the deposited metal.

	- a.There is a significant decrease in the HAZ, which favors the implication that there is a decrease in defects in this region, which has been extensively studied and confirmed to be problematic in several situations.
	- b.In the case of application in low carbon steel, it is concluded that the grain size is slightly reduced, favoring the increase of the mechanical strength of the weld metal. Where several works observed this increase in the hardness of the weld metal. In addition, it was found that there are few changes in the microstructure, where in certain cases, the formation of acicular ferrite, which is very desired in weld metals, is increased.
