METHOD FOR COATING HEARTH ROLL HAVING EXCELLENT HARDNESS OF HIGH TEMPERATURE USING HIGH PRESSURE HIGH VELOCITY OXYGEN FUEL SPRAYING

摘要

PURPOSE: A coating method of hearth roll is provided to increase a high temperature hardness of the coating, to reduce an amount of pores and to reduce a resolution of a carbide by using a high pressure high velocity oxygen fuel spraying. CONSTITUTION: A method is a coating method of hearth roll to form a Cr3C2-M(heat-resistant metal) by using a high pressure high velocity oxygen fuel spraying. A bond coating is formed in a surface of hearth roll by using a powdered particle of heat-resistant metal having 20-50micrometers of a particle size. A coating of 40-100micrometers thickness is formed by using a Cr3C2-xM particle(the x is 20-25wt%) having 20-50micrometers of a particle size. Thereby the coating has a higher hardness of high temperature and a higher surface illumination than an existing coating. The coating is used as the coating of hearth roll surface and reduces a build-up event caused by a contacting with an iron.