Effect of electrolytic plasma polishing on microstructural evolution and tensile properties of 316L stainless steel

Abstract

Abstract Electrolytic plasma polishing (EPP) is an advanced technique for high-quality surface finishing of metal and alloy materials. Austenitic 316L stainless steel (SS) is extensively used in various industrial applications due to its excellent comprehensive performance. Therefore, it is widely studied to improve its properties by specific means and methods and expand its scope of application. In this paper, the influence of EPP generated dynamic composite energy on the microstructural evolution and tensile properties of machined 316L SS is investigated. A decrease in the surface roughness (from 0.103\xa0μm to 0.046\xa0μm), average grain size (from 5.65\xa0μm to 5.21\xa0μm), and low angle grain boundaries (LAGBs) are observed, along with an increase in geometrically necessary dislocation density in post EPP samples. Post EPP, grains are found to be predominantly oriented in 〈101〉. Schmid factor variation (from 0.475 to 0.45) shows a reduction in plastic deformability of the material. The yield strength and tensile strength of the material is increased by 8.98% and 4.32%, approximately, after EPP treatment. The dynamic composite energy produced during the EPP process may induce a cavitational effect, causing (i) rupture of the vapor-gaseous envelope, (ii) high-energy plasma bombardment, and (iii) development of annealing stress inside the material, resulting in microstructural evolution of 316L SS.