from the conferences organized by TANGER Ltd.
Surface treatment methods are often necessary to achieve the desired functionality of parts produced by conventional technologies. Plasma-electrolyte (ELP) technology is an advanced technology for surface treatment. It is based on the phenomena occurring between the metal surface and the electrolyte under DC voltage exceeding 150 V. The process can reduce the surface irregularities and polish the surface to a mirror gloss. The function of tool for reducing the initial roughness is taken over by an ionized steam-plasma envelope that surrounds the entire object during the process. The paper presents the results into polishing of 16MnCrS5 steel utilizing the ELP process. The case-hardened surface layer has demanded two-stage treatment. In each stage, electrolyte of a different chemical composition, concentration, and temperature, and process durations were applied. In the first stage, an electrolyte based on an aqueous solution of ammonium sulphates and chlorides reduced the initial roughness Ra of 0.34 µm more than 50 % within 120 seconds, but a dark coating was detected on surface. In the second stage, an electrolyte based on an aqueous solution of carbonates removed this coating and imparted the surface with a mirror gloss. The final roughness Ra reached value of 0.09 µm. The ELP treatment had a positive effect on the macroscopic character of the steel surface, achieving homogeneity and eliminating traces of grinding tool or other surface macro-unevenness (burrs) that disrupt the surface integrity.
Keywords: Plasma-electrolyte polishing, multistage process, surface roughness reducing, low-alloy manganese-chromium steel© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.