Investigation of Mechanical Properties of Oxide Films Formed on Carbon Steel at High Temperature Corrosive Environments

摘要

The surface degradation of metals that occurs in high temperature corrosive environments has been severe problems of boiler materials in fuel combustion power plant systems. The damage to materials has been often accelerated by mechanical removal of oxide films formed on the material surface. It is therefore very important to investigate mechanical properties and adhesiveness of oxide films at practical high environments, in order to discuss life cycle assessment. Corrosion/oxidation tests were conducted at high temperature corrosive environments of wet air, water steam with hydrogen chloride to look into basic behavior of the corrosion/oxidation. Impact tests were per-formed on the surface of carbon steel covered with oxide films in the same environments to obtain mechanical properties and adhesiveness of the oxide films. It was found that the corrosive environments increased oxidation of carbon steel a little, and that decreased the fracture strength and other mechanical properties of the oxide films.