Avaliação da soldagem em chapas do aço inoxidável superduplex UNS S32750 utilizando o processo arame tubular

Abstract

Superduplex stainless steels (SDSS) may be defined as a family of steels having a two-phase ferritic-austenitic microstructure and the good mechanical properties and high corrosion resistance of this alloy are attributed to the microestrutural balance. These excellent qualities attribute to SDSS great employability in the oil sector, where manufacturing and equipment maintenance are performed by welding, which if not executed properly, can have a negative effect on the metallurgical properties. The objective of this study is to evaluate the influence of welding parameters (Alloy, Stick out,Shielding gas, welding gun orientation, Arc oscillation, Energy technique and Heat input) on quality characteristics (ferrite fraction and microhardness) using the Taguchi method. Results showed that only the alloy, heat input, energy technique and the welding gun orientation, significantly affects the fractions of ferrite and all tests presented values higher than 50%. The microhardness values were not affected significantly by any of the control factors used in this work.