Parameters optimization of electrolytic plasma polishing of austenitic stainless steel and surface performance analysis

Abstract

Electrolytic plasma polishing is a new type of surface finishing technology, widely used for high-quality polishing of metals and alloys due to its excellent processability. In this paper, the austenitic stainless steel (302) is the processing material, and the electrolyte temperature, electrolyte concentration, voltage, and polishing time are used as influencing factors. The surface roughness of the material is used as the evaluation index for electrolytic plasma polishing experiments. The orthogonal experimental group is designed to obtain the best process parameters of electrolytic plasma polishing through range analysis, and the influence laws of various factors on surface roughness is studied. The property of the polished sample from the aspects of surface morphology, elemental composition, X-ray diffraction analysis, hardness changes, and corrosion resistance are characterized. The experimental results show that the surface profile of the polished sample has better consistency, and overall it is flat and smooth, with the original scratches are completely removed. The surface roughness is significantly reduced from the initial 0.3–0.076 μm. The content of Cr element has increased to a certain extent, while the content of Fe element has decreased, and surface impurities have been removed. There is no phase transition on the surface of the sample, the diffraction peak intensity significantly increases, the half width prominently decreases, the crystalline grain size increases, and the surface hardness decreases. During electrochemical test, the self-corrosion potential increases, the self-corrosion current density decreases, and the corrosion resistance of the sample surface increases.