ABSTRACT
A number of versions of the MIG/MAG process has appeared in the market to cope with the welding of joints formed by high thickness sheets without the need for beveling. This originated in the 1980s under the designation of Transferred Ionized Molten Energy (TIME), whereas the 1990s saw the names Rapid Arc and Rapid Melt emerge and in early 2001 the technique was revisited under the name of Buried Arc. These developments did not reveal and do not reveal in principle any special version of the MIG/MAG, but rather showed technical implementations and the conjugation of variables and parameters to improve the geometric profile of the bead obtained, although some submitted patent applications. Recent modern product launches from 2010 on, in a huge profusion of new nomenclatures and many under the aegis that everything depends on a special technology embedded in the welding power sources have overwhelmed the users lately. This paper presents a new interpretation for what is really critical to achieve a high performance of the MIG/MAG process in terms of penetration. The welding power source may be based on the more conventional mode of the process, i.e. in the voltage control mode (CV). However, what the source effectively has to meet is a certain dynamic response in order to sustain a metastable equilibrium of the molten pool that is deepened in the joint in the form of a semikeyhole. The equipment must react very rapidly in the face of a physical contact between the wire-electrode and the weld pool and return to its steady state very slowly. This type of power source reaction is what some manufacturers obtain by the use of pulsed current, but without any correlation with the control of the metallic transfer, as claimed by these manufacturers. The present work presents practical results of both welding and the method to determine the required dynamic behavior of welding sources suitable for this technology.
KEY WORDS: Deep Penetration GMAW; Inductance Control; Current Dynamic; Voltage Control.
Referência:
SILVA, R. H. G.; DUTRA, J. C.; SCHWEDERSKY, M. B.; et al. Dynamically-Flexible Arc – A Novel Interpretation for the High Performance GMAW. In: Proceedings of the Twenty-ninth (2019) International Ocean and Polar Engineering Conference. International Society of Offshore and Polar Engineers (ISOPE) ISBN 978-1 880653 85-2; ISSN 1098-6189. Honolulu, Hawaii, USA, June 16-21, 2019. p. 3930-3936