Anisotropy of microstructure and corrosion resistance of 316L stainless steel fabricated by wire and arc additive manufacturing

This study investigated the dependent relationships between the microstructure and corrosion resistance of the 316L part using wire and arc additive manufacturing (WAAM), through electrochemical methods and multiscale characterization techniques. The results showed that the corrosion resistance strongly depended on anisotropy in the microstructure. On the top surface, fewer track-track fusion lines with weaker element segregation led to the best pitting corrosion resistance. But on the side surface perpendicular to the scanning direction, the narrower ferrite primary dendrite arm spacing, lower ferrite content and more uniform element distribution provided the best general corrosion resistance.