Enhancing the Surface Quality of Additively Manufactured 316 Stainless Steel Revolving Parts through Electrochemical Polishing

Metal additive manufacturing (AM) of revolving parts has wide application across industries such as food, medical, automobile. However, high surface roughness and roundness errors on the outer surface of additively manufactured revolving components limit their performance and commercial viability. Electrochemical polishing (ECP) is a promising post-processing technology that allow achieving smooth and high-quality surfaces. However, conventional ECP relies on polluting and corrosive acid-based solutions with low current densities, limiting the efficiency of polishing. In this study, an eco-friendly NaNO 3 electrolyte is proposed to finish the outer surface of AM 316 stainless steel revolving parts with a sector-shaped tool and at high current density. A simulation model was developed to clarify the underlying polishing mechanism, incorporating critical parameters such as the tool geometry, current density, and the reconstructed 3D part profile. Simulation results provided insights into the finishing efficiency and quality, highlighting the evolution of surface roughness along the axis and roundness error around the circumference. Experimental ECP trials confirmed the simulation findings, producing a smooth, shiny surface with performance comparable to the original parts. This approach effectively reduced the average surface roughness Ra to 1.36 μm and roundness error 0.03 mm, demonstrating a homogeneous polishing outcome.