| 摘要 |
PROBLEM TO BE SOLVED: To effectively prevent the development of build-up even in the case of using a hearth roll for long time under high temp. oxidizing or reducing atmosphere in a heat treatment furnace, by forming the roll outer layer of a refractory having specific composition composed of Al2O3, CaO, MgO and SiO2 on the hearth roll. SOLUTION: This hearth roll for heat treatment furnace, excellent in the build-up resistance is obtd. by forming the roll outer layer of the refractory composed of 35-50 wt.% Al2O3, 4-10 wt.% CaO, 5-10 wt.% MgO and the balance SiO2 with inevitable impurities to about 20-40 mm thickness. This roll outer layer can be formed by winding refractory fibers which are obtd. by adding aluminum oxychloride, calcium nitrate, magnesium nitrate and silica gel into solvent and spinning and burning the mixture at about 1100-1300 deg.C, on the steel-made roll inner layer material, and compressing it. This hearth roll is especially effective to be used to a furnace for continuously annealing a stainless steel strip at <=1200 deg.C.
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