Mitigating the susceptibility to intergranular corrosion of alloy 625 by friction‑stir welding

• Autor(a) principal: Lemos, Guilherme Vieira Braga
• Data de Publicação: 2022
• Outros Autores: Farina, Alexandre Bellegard, Cardoso, Henrique Ribeiro Piaggio, Bergmann, Luciano Andrei, Ferreira, Jane Zoppas, Santos, Jorge Fernandez dos, Voort, George Vander, Reguly, Afonso
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/237282
• topic: Soldagem por fricção; Ligas de níquel; Resistência à corrosão

In this work, friction-stir welding (FSW) was employed to alloy 625 grade I (soft annealed) sheets. Therefore, solid-state based welding was undertaken with a tool rotational speed of 200 rpm and a welding speed of 1 mm/s. Microstructural features were analyzed by light optical and scanning electron microscopy (LOM and SEM). Moreover, microhardness measurements were performed. The susceptibility to intergranular corrosion was verifed by the double-loop electrochemical potentiokinetic reactivation (DL-EPR) test. Complementary, intergranular corrosion was also evaluated by the ASTM G28 Method A. FSW promoted grain refnement, increased microhardness, and reduction in the degree of sensitization. Finally, the mean corrosion rate observed in the ASTM G28 Method A test was 0.4406 mm/year, which suggests a good weld quality.