Evaluation of Mechanical Properties for Chromium Carbide Coatings at High Temperature

Abstract

High-temperature erosion and erosion-corrosion are significant problems for energy conversion systems in power plants. The source is high-temperature dry steam that contains iron oxide and fly ash particles. Compared with high-temperature alloys, ceramic coatings generally have higher resistance to high temperature corrosion and erosion. However, it would be very difficult to obtain mechanical properties for ceramic coating materials in a high temperature environment. With no experimental testing, therefore, the performance of ceramic coatings in an actual plant environment is not typically evaluated before field application. The aim of this paper is to discuss dynamic hardness and fracture toughness as mechanical properties of ceramic coating materials at high temperature, compared with those at room temperature. We chose three types of chromium carbide coating materials that were coated with atmospheric plasma spray (APS), vacuum plasma spray (VPS), and high-velocity oxygen fuel (HVOF) on SUS430 stainless steel.