| 摘要 |
PROBLEM TO BE SOLVED: To provide a hearth roll capable of withstanding use for a long period of time without allowing easy destruction of a zirconia coating film formed on a roll surface even when used for a long period of time in an annealing furnace for manufacturing a high tensile strength steel sheet containing a large amount of Mn as an alloy element.SOLUTION: In the hearth roll, a plurality of layers of coating films are formed by thermal spraying on a body peripheral surface of a roll base material. The hearth roll includes, on the body peripheral surface of the roll base material, in order from a lower layer side; a first layer coating film comprising an MCrAlX alloy (wherein M is one or more kinds selected from Co, Ni and Fe, and X is one or more kinds selected from Y, Hf, Si and Ta); a second layer coating film comprising stabilized zirconia containing 15-30 mass% CeOas a stabilizer or comprising ceramics whose body is the stabilized zirconia; and a most outer layer coating film comprising stabilized zirconia containing 30-40 mass% CeOas a stabilizer or comprising ceramics whose body is the stabilized zirconia. |
