Metal additive manufacturing (AM) generally requires removal of support structures through costly post processing which may limit part design and complexity. A novel process developed at the Colorado School of Mines has dramatically simplified post processing by sensitizing and selectively corroding support material. While this process has been proven for 316L stainless steel, the corrosion response of the stainless steel after etching is unknown. To determine whether the corrosion-resistant properties of the stainless steel are maintained, this paper evaluates additively manufactured 316L stainless steel specimens after they have undergone the sensitization and etching process. The corrosion response in NaCl of 316L laser powder bed fusion (L-PBF) parts were evaluated as a function of build orientation and post-processing parameters. Electrochemical data was combined with metallographic analysis to connect corrosion mechanisms to the underlying microstructure and, ultimately, the processing conditions.

Key words: corrosion resistant materials, metals, additive manufacturing, electrochemistry