MIG/MAG - short-circuit metal transfer - control of the current wave form - fundamentals of the CCC and STT systems


Abstract:

This work covers short-circuit metal transfer in theMIG/MAG process, where the current is the direct regulation variable, in contrast with the conventional mode in which the direct regulation variable is the voltage. It sets out the general theory for this technique and describes a new system, not yet commercially offered, developed by LABSOLDA at UFSC. The control bases of the process are described, presenting oscillograph results and performance results in relation to root passes and production of splatter. In addition, some results from an existing commercial system are set out with the aim of making direct comparisons between the control strategies and the implications for the largest dependent factors, such as drop diameters, average current, arc efficiency and arc power. Questions are posed such as the criteria for monitoring the variables and the calculations for arc power, which are as important for these new technologies as they are in the case of conventional systems.

Keywords: metal transfer; controlled short circuiting; metal transfer control

Referência:

Dutra, Jair Carlos and Silva, Regis Gonçalves e(2009)'MIG/MAG - short-circuit metal transfer - control of the current wave form - fundamentals of the CCC and STT systems',Welding International,23:3,181 — 185