Impact of electrolyte concentration on surface gloss in electropolished stainless steel

Electropolishing is a surface finishing process of metals and alloys that enhances brilliant surface finishes with low surface roughness values. The most widely used electrolytes for the electropolishing of stainless steel are varying concentrations of phosphoric and sulphuric acid, and occasionally additives such as chromic acid. The objective of this study was to assess the performance of three commonly used industrial electrolytes in terms of the surface gloss of electro polished stainless steel AISI 316L. Each electrolyte had varying sulphuric-phosphoric acid combinations with or without chromic acid. The following electropolishing conditions were assessed: current density, bath temperature, electropolishing time, electrode position, and initial surface texture. The results revealed that adding chromic acid to the electrolyte did not significantly enhance gloss ranges. Current density and electropolishing time were the most significant parameters of surface gloss.