Abstract
Of the arc welding processes, MIG/MAG has the greatest number of innovations, with an enormous quantity of new versions originating. Because of this, end users are faced with great difficulty in keeping up to date with the state of the art and making correct decisions, whether in the selection of new equipment, selection of correct welding mode and adjustment of equipment already available. Many of the novelties come on the market with a technological appeal that not always corresponds to scientific truths. This paper aims to contribute to this question by addressing cold metal transfer (CMT). A study of melting characteristics is presented, providing comparisons with the conventional, shortcircuiting MIG/MAG process for welding naval aluminium 5183. The results show that the apparent low power of CMT, suggested by the low mean value of voltage and current, is not correct. For the conditions tested, it is a version of the MIG/MAG process with more power than the conventional, when the calculation procedures are correct. Nevertheless, CMT is verified to be a good solution for aluminium root pass welds due to the adequate cadence and droplet transfer repeatability. The current and voltage cadence is very similar to a rectangular pulse wave, but inside a short-circuit transfer range.
Keywords: welding power; cold metal transfer; conventional MIG
Reference:
DUTRA, Jair Carlos; SILVA, Régis Henrique Gonçalves e; MARQUES, Cleber. Melting and welding power characteristics of MIG–CMT versus conventional MIG for aluminium 5183. Taylor & Francis Online. Welding International, Out. 2014