Experimental Investigation of Corrosion Behavior of Plasma Sprayed Cr2O3 Coatings on 410 grade Steel

Abstract

Thermal spray technique has emerged as a very effective surface engineering technique to protect the underlying base material from wear, erosion, corrosion and other adverse operating conditions. The present investigation deals with air plasma spray technique to deposit Cr2O3 particles on grit blasted 410 grade steel. Morphological and chemical composition of the coating was analyzed by scanning electron microscope (SEM) and EDX spectrum. Micro hardness and porosity of the coating was also investigated. Corrosion studies were carried out using salt spray apparatus for different time period (50,100,150, 200hrs) in 5% NaCl fog medium as per ASTM B117 standard. The corrosion rate was calculated on the basis of coating mass loss with respect to time. The effect of test duration on the corrosion behavior is analyzed and reported. The experimental results indicate that the dense and hard Cr2O3 coating exhibits superior corrosion resistance as compared to un-coated steel substrates.