| 摘要 |
PROBLEM TO BE SOLVED: To improve the stable use of a body part in an electric furnace small ceiling precast block, especially by improving a spalling resistance property and a material with improved welding loss resistance and heat resistance around an electrode hole. SOLUTION: In a precast block of an electric furnace small ceiling, an electrode hole periphery block 4 made of Al2 O3 -Cr2 O3 material is combined with a different material of a body part 1 being made of Al2 O3 -SiO2 material and a mixture layer (a shaded part) 5 between them being made of Al2 O3 -SiO2 -Cr2 O3 is provided at the boundary part, thus forming a one-piece forming body. When a precast block for electric furnace small ceiling is practically used for an electric furnace 80T, the durability of the electric furnace small block can be improved by 35-50% as compared with before by suppressing damage around an electrode hole and the damage of a joint part. |
