Uma contribui?§?￡o ao processo de soldagem plasma de arco transferido (PTA) para posi?§?μes for?§adas

摘要

In this Project, besides of producing an equipment of plasma welding with injection of powder (PTA), studies were done with the purpose of contributing to the welding in flat, horizontal and overhead. The welding torch was developed starting from a Plasma torch for the keyhole. Furthermore, the adaptation proyect allows the use of two constrictor plasma nozzles with different convergency angles for powder feeding. For this proyect, two models were built, a nozzle with a 30?o angle and another one with a 60 ?o convergency angle. With this, a new perspective is opened for metallic coverings out of a flat position and within this context it is inserted the recovery of the welding of eroded parts due to the cavitation of hydraulic turbines. With the purpose of knowing the behavior of the process out of position, some experiments were done with pulsed continue current by using the alloy of Stellite 6 and they were compared with the results obtained in the flat and horizontal position. The Stellite 6 alloy is being one of the most useful since it presents an excellent resistance to erode by abrasion, impact, erosion and cavitation. The geometric characteristics of the wires are evaluated, dilution degree, hardness and microestructure. In the horizontal position and overhead, the results found were unknown, making LABSOLDA the pioneer in recoverings outside the flat position in this welding process.