Carburizer and carburization method using same

Abstract

This carburizer for carburizing molten iron housed in an electric furnace or a ladle, is a mixture of calcined lime and a carbon material having an ash content of 5-18 mass%, and satisfies the conditions 0.6<=(mc+Mc) / ms<=2.7 and 0.7<=(mc+Mc) / ma<=6.5. This carburization method uses said carburizer. Here, mc represents the mass of CaO in the carbon material, ms represents the mass of SiO2 in the carbon material, ma represents the mass of Al2O3 in the carbon material, and Mc represents the mass of the calcined lime.

Description

technical field [0001] This application relates to the carburizing material for efficiently carburizing in an electric furnace or a ladle, and the carburizing method using the same. Background technique [0002] Conventionally, cold iron sources such as iron scrap, pig iron ingots, and direct reduced iron have been melted and refined in electric furnaces to produce steel used in building materials, etc. The main energy source of this electric furnace is arc heat, but for the purpose of promoting melting and refining and saving expensive electric energy, auxiliary heat sources such as oxygen (for oxidizing and melting iron), gas fuel, liquid fuel, and powdered coke are also used. [0003] In addition, a solid carbon material is added to molten iron as a recarburizing material to increase the carbon content of the molten iron, and carbon in the molten iron is burned with oxygen as an auxiliary heat source. As the carbon-increasing material, artificial graphite, earthy graphit...

AI Technical Summary

Problems solved by technology

However, at present, due to problems such as fluorine elution from slag, fluorine-free materials are required as sub-materials, and their use is limited.

In addition, Patent Document 6 shows a recarburizing material in which 20% by mass to less than 80% by mass of CaO is mixed with a carbon material. However, since the ratio of CaO is large, the cost becomes high.

In addition, Patent Document 7 discloses an adjustment method in which the mass ratio of CaO / C is adjusted so that the mass ratio of CaO / C becomes 18 or more in the RH vacuum degassing process, and a recarburizing material is added by top blowing, but this method There is also a problem that the ratio of CaO is large. In addition, the carbon concentration in the molten steel increases in the range of 0.005 to 0.010% by mass, which is very different from the production of molten iron in a general electric furnace.

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