Soldagem plasma "Melt-in" de aço comum ao carbono

Abstract

As a consequence of market increasing demand for more competitive manufacturing techniques, an increasingly role has been reserved in the industrial field for the Plasma welding process, although still restricted use to more developed countries. Among the main obstacles that prevent a thorough dissemination of this process, equipment and accessories costs and lack of know-how on welding parameters setting appear. Notwithstanding these deficiencies, the melt-in version of the Plasma welding process, which is normally employed with Argon as plasma and shielding gas, presents considerable limitation in the welding speed, due to the occurrence of bead irregularities. Taking into account the Plasma welding process potential, the feasibility of this manufacture option may represent a spin-off in automate unions of overlap, groove or edge joints, with great impact in the assemble productivity of goods such as autoparts, refrigerator compressors and other white-line components and even of the so-called tailored blanks. Thus, the aim of this work was to propose and evaluate a novel welding procedure for melt-in Plasma welding, which includes an original consumable formulation. This approach aims at a significant increase of the operational speed in low-carbon-steel thin-plate unions. The goal is to present to the market an option for a welding process with high production rate without the need of filler metal (autogenous weld). After the tests, a family of gas blends with high performance was found. It was verified that it is possible to increase the welding speed over 400% in relation to that speed obtained using Argon, without compromising the quality of the beads and weakening the joint, as long as procedures for joint cleaning and torch positioning are observed.