Improving the Pitting Corrosion Performance of Additively Manufactured 316L Steel Via Optimized Selective Laser Melting Processing Parameters

Additive manufacturing (AM) has many advantages over conventional manufacturing methods, such as the ability to produce free-form complex shapes and materials with unique properties. Nevertheless, the implementation of AM components into corrosive environments is ultimately limited by the poor corrosion performance of the printed materials when compared to their conventionally manufactured counterparts. In this study, we demonstrate improvement and tailoring of corrosion resistance in AM parts via precise control of laser processing parameters, which were adjusted to optimize pitting corrosion performance for fully dense parts of austenitic stainless steel 316L. Laser power, speed, and hatch spacing were systematically varied while maintaining a constant energy density in a laser powder bed fusion (L-PBF) AM system. Powders were consolidated via selective laser melting (SLM) to establish the parameters influencing pitting performance through potentiostatic anodic oxidation. The results show a strong correlation between processing parameters and resistance to pitting corrosion, attributed to laser velocity-induced variations in microstructure and residual stress state.