Hearth roll with a thermal spray coating and thermal spray cermet material including a high thermal expansion coefficient hard oxide

摘要

PURPOSE: To provide a hearth roll having the film excellent for the peeling resistance the thermal shock resistance, and the wear resistance by executing the thermal spraying of the cermet layer consisting of the oxide ceramics and the specified metals on the surface of the hearth roll to be used in a heat treatment furnace. ;CONSTITUTION: A hearth roll to be used in a heat treatment furnace for steel such as a continuously annealing furnace is manufactured of Cr-Ni alloy steel excellent for the heat resistance, and the cermet having the composition consisting of 50vol.% oxide ceramics having the composition consisting of, by weight, 60% Al₂O₃ and 35% CeO₂ or 20% Y₂O₃ and the balance ZrO₂, and the balance two or more kinds of metals such as Ni, Co, Cr, Al, Si, Nb, Ta, and Y is thermally sprayed with the thickness of 150μm. The hearth roll is developed where the heat shock resistance is excellent even when used in the furnace of high temperature, and the peeling resistance and the hardness for the stock roll are large, and the wear resistance is excellent, the thermal expansion coefficient is high with less built-up, and the cermet film is excellent for the heat shock resistance even when used in a furnace of high temperature.;COPYRIGHT: (C)1995,JPO