Parametric Investigation of EP To Enhance Surface Characteristics of Maraging Steel With Organic Electrolyte

Abstract

Maraging steel 300 is widely used in aircraft, tools, and automotive industries, which requires a polished surface for better performance. In conventional methods of polishing, the abrasives directly contact the workpiece surface and deteriorate its property. Thus, a non-conventional method like Electropolishing (EP), is utilized to finish maraging steel with acetic acid (99.7 wt.%) and perchloric acid (70 wt.%) mixed in the volume of 3:1. Linear sweep voltammetry (LSV) is performed to determine the passive region that gives the best electropolishing performance. Different parameters, namely temperature, agitation, and polishing time and their effect on surface roughness and surface reflectance, are observed during EP. The optimized process parameters which give the best EP performance are the temperature at 60ºC, rotation of magnetic stirrer at 400 rpm, and polishing time of 6 minutes. An improvement of 56% in surface roughness and 60% in surface reflectance from its initial value of 21% is observed. EP makes the surface hydrophilic as the contact angle changes from 111.2º to 68.6º. Energy-Dispersive X-Ray Spectroscopy analysis suggests that after EP, a metal oxide layer forms on the surface which helps in increasing corrosion resistance.