| 摘要 |
<p>PURPOSE:To prevent deterioration in the surface quality of a steel sheet to be heat treated due to the build-up of scale by cladding the outside periphery of a heat resistant cast steel core with a heat resistant alloy steel sleeve having a specified composition to form each hearth roll for a heat treating furnace. CONSTITUTION:When a metallic strip such as a steel sheet is heat treated by heating in an atmospheric gas in a heat treating furnace, each hearth roll formed by cladding the outside periphery of the heat resistant cast steel core with a heat resistant alloy steel sleeve contg. <0.1% C, <1.5% Si, <1.0% Mn, 17-21% Cr and 0.1-4.0% Al is used to transfer the steel sheet in the furnace. Since scale does not build up on the hearth roll, the formation of a pickup press mark on the surface of the steel sheet due to the build-up of scale is prevented, and a heat treated steel sheet having superior surface quality is obtd.</p> |
