Influência da adição de arame frio ao processo MIG/MAG na área fundida e falta de fusão dos cordões depositados.

Abstract

The MIG/MAG welding process has great potential not only in the area of joining metals, but also in the area of deposition manufacturing, such as additive manufacturing. Techniques that add benefits to the process are in high demand. In this work, the influence of adding cold wires to the MIG/MAG process on the geometric characteristics of the weld bead was evaluated, also revealing the difficulties involved during the application. Cold wire was added in different arrangements: a single cold wire and two cold wires fed at the same time. Both arrangements were compared with the condition without the use of cold wire. Wire of three different diameters were used: 0.6, 0.8 and 1 mm. In addition, the maximum feeding speed was determined. The experimental bench consisted of a welding robot, a MIG/MAG welding station, a cold wire feeder and a wire guide. Tests have shown that the addition of cold wire to the conventional MIG/MAG process is advantageous for bead characteristics. Using the same amount of energy, an increase in the amount of material deposited and a reduction in the molten area of base metal was obtained. However, an excessive increase in the cold wire feed speed can result in an excessive reduction in the molten area of base metal and may even lead to fusion failures. When adding a larger diameter cold wire, as well as adding two cold wires, the influences are more evident at lower feed speeds.