Abstract
Additive manufacturing (AM) is a rapidly growing metal processing technique that not only enables the making of complex geometries that are difficult to produce by using traditional methods. Stainless steel 316L displays high resistance to localized corrosion attack by chloride due to the presence of molybdenum and chromium leading to the formation of a stable passive film. In this work, we aim to characterize and compare the active-passive characteristics of stainless steel 316L manufactured using directed energy deposition (DED) and selective laser melting (SLM) techniques. The effect of anisotropy was also studied by obtaining samples perpendicular and parallel to the building direction. The testing solution used was 3.5 wt% NaCl maintained at a pH of 8 adjusted by borate buffer. A comprehensive understanding of corrosion performance of materials was obtained by testing using cyclic polarization (CP) and electrochemical impedance spectroscopy (EIS). The tested alloys were characterized to understand the mechanism of chloride attack on the microstructural features of the AM alloy.