PTFE THIN FILM COATING ON 316L STAINLESS STEEL FOR CORROSION PROTECTION IN ACIDIC ENVIRONMENT

Abstract

Stainless steels (SS) are the most common materials used in various engineering applications because of their fine mechanical and excellent corrosion resistance properties in different mediums. 316L SS shows poor corrosion behavior in HCL. Hard coating is often required for protection of 316L SS from wear and corrosion. In this research paper polytetrafluoroethylene (PTFE) was coated on 316L SS by spin coating technique to modify their corrosion resistance in acidic media containing Hydrochloric acid (HCL). The anticorrosion property of the 316L SS and PTFE coating was studied in 40% HCL by electrochemical corrosion test and potentiodynamic polarization curves at room temperature and compared. The morphology of uncoated and coated substrates were examined by scanning electron microscopy (SEM) while the compositional analysis performed through energy dispersive x-ray spectroscopy (EDX). The morphology of the coated and uncoated substrates were also studied before and after electrochemical corrosion test and then compared. The thickness of the coating was also examined well. The result shows the remarkable improvement in the corrosion resistance of PTFE coating by decreasing the corrosion current density in HCL media.