Desenvolvimento e análise de técnicas de soldagem de reparos com deposição em dupla camada de aços inoxidáveis AWS ER309L e AWS ER347 aplicados sobre aços estruturais 2,25Cr-1Mo e 2,25Cr-1Mo-0,25V

• Autor(a) principal: Andrade, Tathiane Caminha
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Ceará (UFC)
• Texto Completo: http://www.repositorio.ufc.br/handle/riufc/18254
• topic: Ciência dos materiais; Soldagem; Aço inoxidável

The right choice of welding processes and parameters for a specification of a welding procedure for the manufacture or repair is an essential factor and can represent the success or the failure of overlay metallic components. Depending on the application, it is necessary that the material and also the weld region have suitable specific properties for requests from operating conditions of these components such as high stresses and high temperatures. This work aims to contribute to a study for the development and evaluation of techniques of welding overlay without post-weld heat treatment (PWHT) with AWS ER 309L and AWS ER 347 austenitic stainless steels for repair of 2,25Cr-1Mo (ASTM A387 Gr 22) and 2,25Cr-1Mo-0.25V (ASTM A832 Gr. 22V) structural steel plates. The base metals (2,25Cr-1Mo and 2,25Cr-1Mo-0.25V) and filler metal (AWS ER 309L and AWS ER 347) were characterized and evaluated chemical composition, microstructure and hardness tests. The preliminary welding was performed with a factorial planning analyzing shielding gas, filler metal, energy technique, welding heat input and arc waving. In this step, the welding were made in single weld bead with preheating at 175 C. Specimens were taken from the central region of the weld and analyzed by hardness and microstructure criteria for establishment the Decision Diagrams. The analysis of these diagrams show the main parameters that could result in good overlays and the overlay welding was performed according to the choice of these parameters. The results shown that the welding performed using the temper bead technique aiming to refining tempering the GGHAZ first layer was possible to improve the properties of that region. For 2,25Cr-1Mo steel the temper bead technique gave hardness below 250 HV in the HAZ of this material and for 2,25Cr-1Mo-0,25V steel the results did not meet the maximum hardness established by standard, but still there was an intense refining and tempering.