Uma Contribui?§?￡o ao Estudo do Processo TIG Cold Wire na Posi?§?￡o Plana, Horizontal e Sobrecabe?§a sob Novos Desenhos de Tocha e Metodologias de Alimenta?§?￡o de Arame

摘要

This line of research aims to improve the current boiler tube welding procedure, where processes for manual welding are used and the quality of the welded joints depends exclusively on the skill of the welder. In this regard, the proposal aims to carry out the reparation using a more productive welding process called cold wire TIG, with mechanical cold wire feeding, with the intention of getting better quality and repeatability in the welded joints. We evaluated the surface appearance, morphology, degree of dilution and convexity rate of the weld beads. Assays were performed with two wire guide manipulators (20?° and 48?°) to verify the influence of the entry angle of the wire injection at the arc. The results indicated that there is a considerable increase in TIG productivity with mechanical wire feeding when the guide manipulator with a wire entry of 20?° is used, approaching the deposition rate obtained with the MIG/MAG welding process for the same wire diameter. It was possible to test two wire feed settings: continuous and pulsed. These results show that the proposed configuration of pulsed wire feeding was successfully applied in all positions ensuring repeatability, process stability and sustenance of the weld pool.