High-Temperature Erosive Behavior of Plasma Sprayed Cr3C2-NiCr/Cenosphere Coating

Abstract

This research examines the deposition of Cr<inf>3</inf>C<inf>2</inf>-NiCr/cenosphere and Cr<inf>3</inf>C<inf>2</inf>-NiCr coatings on MDN 321 steel through the process of plasma spray. In this process, the solid particle erosion test is established at 200, 400, 600 °C with 30° and 90° impact angles. Alumina erodent is adopted to investigate the erosive behavior of the coating at higher temperatures. The properties of the Cr<inf>3</inf>C<inf>2</inf>-NiCr/cenosphere coating are established based on the microhardness, the adhesive strength, the fracture toughness, and the ductility. To quantify volume loss as a result of erosion, an optical profilometer is used. At higher temperature, decrease in the erosion volume loss of Cr<inf>3</inf>C<inf>2</inf>-NiCr/cenosphere and Cr<inf>3</inf>C<inf>2</inf>-NiCr coatings is observed. The erosion-resistive property of Cr<inf>3</inf>C<inf>2</inf>-NiCr/cenosphere coating is higher than that of MDN 321 steel by 76%. This property is influenced by high-temperature stability of mullite, alumina, and protective oxide layer that is formed at elevated temperatures. The morphology of eroded coating discloses a brittle mode of material removal. © 2018, ASM International.