Influence of welding current in plasma–MIG weld process on the bead weld geometry and wire fusion rate

Abstract

One of the versions of the plasma–metal inert gas (MIG) process is basically a combination of a plasma arc with a MIG/metal active gas (MAG) arc in a single torch. With this association, the advantages of each arc are combined. The main characteristic of this is the independence between the heat input by the process and the deposited material, resulting in greater facility to control bead weld geometry. In the current literature, there is a shortage of information related to the process, and most of this goes back to the 1970s and 1980s when the technology available was not able to make the process viable for industry. However, in recent years, the use of the diffusion of new electronic power sources used in welding has sparked up again the interest in plasma–MIG process. In this context, this paper aims to contribute to the studies related to the influence of the MIG and plasma current balance on the geometry of the bead weld and wire fusion rate. Bead-on-plate welds were carried out with plasma and MIG/MAG current combinations at three levels each, keeping, by welding speed corrections, the bead volume the same. It was observed that the introduction of the plasma current over the MIG/MAG current reduces penetration and dilution and leads to convex beads. On the other hand, the use of plasma current increases the MIG/MAG wire fusion rate. However, it seems that the intensity of the plasma current is not the governing parameter of those changes.

Keywords:

• welding
• plasma–MIG
• hybrid arc

Acknowledgements

The authors thank the Faculty of Mechanical Engineering of UFU and its Research & Development Centre for Welding Processes (Laprosolda) for the opportunity to use the equipment and technical support provided and FAPEMIG agencies (TECH. Procedure 1763/06) for the concession of financial resources and the CNPq for the concession of study and research grants for the authors.

Notes

1. [email protected].

2. [email protected].

3. [email protected].

4. [email protected].

Published with permission from ABCM – Brazilian Association of Engineering & Mechanical Sciences – Article originally presented at the 5th COBEF, Belo Horizonte, State of Minas Gerais (MG), April 2009.

Additional information

Notes on contributors

Andre Alves de Resende

1 1. [email protected].

Valtair Antonio Ferraresi

2 2. [email protected].

Americo Scotti

3 3. [email protected].

Jair Carlos Dutra

4 4. [email protected].