PURPOSE: To cast an ingot having high cleanness by executing lining having fire-proof heat insulation and exothermic property in a rectangular mold and solidifying molten steel surface poured at last stage.
CONSTITUTION: The mold 2 of the rectangular frame body is laid on a base plate 1 and the molten steel is poured to start to solidify from a bottom face 52. The solidification at side direction is restrained by the lining 21. Further, heat insulating material 3 may be charged on the face 51 for heat insulation. In this result, the solidification is processed under condition of ascending in parallel the boundary 53 of solidus and liquidus, formed almost horizontally. Therefore, the segregation is substantially disappeared, and even if it exists, as it is concentrated to the ingot surface, in case of needing, it is removed by only light grinding, to be possible to send to a rolling process. Development of coarse carbide in high carbon steel is effectively prevented. As non-metallic inclusions are easily floated and separated, they are not enclosed.
IKEDA MASANORI
KAWABATA SHINICHI
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