Anisotropic behavior of super duplex stainless steel fabricated by wire arc additive manufacturing

Abstract

Broadening the understanding of the anisotropic behavior of super duplex stainless steel (SDSS) fabricated by wire arc additive manufacturing (WAAM) can provide valuable insights for designing and optimizing WAAM components. The purpose of this study is to investigate the anisotropic behavior between mechanical properties, corrosion resistance, microstructure and crystallographic features of wire arc additive manufactured (WAAMed) SDSS thin-wall component, by means of optical microscopy (OM), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), X-ray diffraction (XRD), hardness testing, tensile testing and electrochemical corrosion testing. Meanwhile, a control sample set prepared from commercial hot-rolled SAF 2507 SDSS was also investigated for comparison. The results show that the mechanical properties and corrosion behaviors of WAAMed SDSS are anisotropic, which are attributed to the nonequilibrium phase ratio and anisotropic crystal features in the as-built WAAMed SDSS affected by the repeated thermal cycles inherent to WAAM process.

Keywords

• Super duplex stainless steel
• Wire arc additive manufacturing
• Mechanical properties
• Corrosion resistance
• Anisotropy