METHOD FOR CONTROLLING A SEGREGATION OF STEEL INGOTS BY PURIFICATION OF MOLTEN STEEL

摘要

A method for controlling A segregation of steel ingots by purification of molten steel comprises the following steps: requiring the content of P to be less than or equal to 0.005wt% during the tapping of an electric furnace, to prevent steel slag from entering a ladle; pre-deoxidizing molten metal by using a vacuum carbon deoxidizing process, wherein conventional aluminum deoxidant is used at a small amount or is not used to reduce the amount of impurities; performing deep desulfuration by utilizing an LF, removing the impurities, controlling oxygen content and requiring the content of sulphur to be less than or equal to 0.005wt%; and deoxidizing and degassing under high vacuum to remove the impurities and control the purification of the molten metal, so that the content of full oxygen is less than or equal to 15 ppm, and an ideal value thereof is less than or equal to 10 ppm. By using the purified smelting and pouring control technology, the method reduces the content of the impurities and particularly oxides in the molten metal effectively, thereby solving the problem of A segregation of steel ingots and continuous casting blanks, and significantly improving the internal quality of the steel ingots. The method is applicable to the manufacturing of round ingots and flat steels of various specifications as well as ordinary continuous casting blanks and large-section vertical continuous casting blanks of various specifications.