INGOT METHOD FOR MANGANESE-CONTAINING ULTRA-LOW CARBON STEEL

摘要

PROBLEM TO BE SOLVED: To provide an ingot method for manganese-containing ultra-low carbon steel capable of reducing the amount of use of metal Mn from a conventional method, and executing the processing in a vacuum degassing apparatus with the scheduled casting start time.;SOLUTION: The ingot method for manganese-containing ultra-low carbon steel, in which the target Mn concentration is 0.3-3.0 mass%, is improved as follows: the scheduled casting start time of this time's charge is determined by predicting the time, at which the continuous casting of a previous charge is ended, by the casting rate; the allowance time from the present time to the scheduled casting start time is calculated when starting the vacuum degassing processing; the decarburization processing-possible time is obtained by subtracting the required time for killed processing in the vacuum degassing processing, the required conveying time of molten steel to continuous casting facilities after the vacuum degassing processing is completed, and the casting preparation time from the allowance time; the charging amount of Fe-Mn alloy to be added into molten steel is determined before starting the processing so that the decarburization processing can be executed within the decarburization processing-possible time; and the difference, between the expected Mn concentration in the molten steel after charging the Fe-Mn alloy and the target Mn concentration of a steel product, is adjusted by adding metal Mn in the molten steel during the killed processing.;COPYRIGHT: (C)2012,JPO&INPIT