Hearth roll in a continuous annealing furnace and its production method

摘要

The hearth roll for a continuous annealing furnace is able to suppress the occurrence of buildup on the hearth roll surface and able to be stably used for a long period under the high temperature environment. The hearth roll has a cermet coating comprised 50 to 90 vol % of ceramic and the balance of a heat resistant alloy on its surface, the ceramic containing Cr₃C₂: over 50 to 90 vol %, Al₂O₃: 1 to 40 vol %, Y₂O₃: 0 to 3 vol %, and ZrB₂: 0 to 40 vol % and having a balance of unavoidable impurities and pores, the heat resistant alloy containing Cr: 5 to 20 mass %, Al: 5 to 20 mass %, and one or both of Y and Si: 0.1 to 6 mass % and has a balance of one or both of Co and Ni and unavoidable impurities.