| 摘要 |
PURPOSE: To prevent the development of surface defect of longitudinal crack, etc., on a cast slab by thermal-spraying cermet having a specific thickness on the surface of a mold. CONSTITUTION: The cermet is thermal-sprayed at 50-500μm on the surface of the mold. Since the longitudinal crack is controlled in the initial stage solidifying condition till about 100mm below the molten metal surface, the thermal-spray may be executed in the range to >=100mm below from a meniscus. Since the thermal-sprayed grain diameter is coarsed, such as 10-100/μm, the thermal- sprayed layer has high porosity and low thermal conductivity. Therefore, the solidified shell is slowly cooled and the development of the longitudinal crack is prevented. Further, good effect to the prevention of the longitudinal crack is obtd. by applying metallic plating on the thermal-sprayed layer having 100-2000/μm. The plating is prevented from sticking of powder for continuous casting to the thermal-sprayed surface.
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