| 摘要 |
PURPOSE:To provide a surface coating material for ingot making with which the generation of surface flaws such as net cracking of a slab is thoroughly eliminated by specifying the content of C in the SiO2-Al2O3-CaO ingot making surface coating material to be used for making an ingot of a molten Cr-contg. steel to a prescribed value or below and forming the same into a powdery shape. CONSTITUTION:The content of C in the SiO2-Al2O3-CaO ingot making surface coating material having the compsn. consisting preferably of 25-75wt% SiO2, 3-10wt% Al2O3 and 15-50wt% CaO as the base compsn. is specified to <=2wt% and said material is formed to the powdery shape. The grain size of the powdery material is preferably about 1mm and the material is advantageously usable if the grain size thereof is about 0.5-3mm. The generation of surface flaws such as net crack is thoroughly eliminated by using such ingot making surface coating material. The cost for conditioning the slab is thus reduced and the yield of the slab is improved. The stable production of the Cr-contg. steel is made possible.
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