Investigations on the corrosion behavior of additively manufactured stainless steel

Michael Melia and Eric J. Schindelholz

Sandia National Laboratories

Additive manufacturing (AM) has grown in popularity in recent years with the desire to rapidly prototype metallic parts with designs and structures unobtainable with traditional subtractive processes. With numerous varieties of AM techniques, the choice to use one is based on the desired resolution (ranging from <100 µm to several mm) of the part as well as the desired source material (powder or wire). Regardless of the AM technique, non-equilibrium microstructures, irregular surface structures, and processing defects are common and impact the bulk and surface properties of the AM part. A majority of the active work has been performed to validate these AM components by their mechanical properties, while few investigations focus on the corrosion behavior with respect to components unique microstructures and defects. This presentation compares the well known corrosion behavior of a wrought alloy in hot rolled 304L to 304L fabricated with two prominent AM techniques, powder bed selective laser melting (SLM) and direct energy deposition (DED), with an emphasis on the AM defects and microstructures which lead to the breakdown of passivity in chloride containing aqueous solutions. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.