High-grade non-oriented silicon steel with excellent magnetism and smelting method for high-grade non-oriented silicon steel

Abstract

The invention discloses a method for smelting high-grade non-oriented silicon steel with excellent magnetism. The method comprises the following steps of: 1) smelting, namely smelting the following chemical components: less than or equal to 0.005 weight percent of C, 2.6 to 3.4 weight percent of Si, 0.2 to 0.5 weight percent of Mn, less than or equal to 0.2 weight percent of P, less than or equal to 0.005 weight percent of S, 0.3 to 1.6 weight percent of Al, less than or equal to 0.005 weight percent of N, less than or equal to 0.005 weight percent of O, less than or equal to 0.0015 weight percent of Ti, and the balance of Fe and inevitable inclusions, and modifying ladle top slag in the tapping process of a converter so as to ensure that the ladle top slag comprises 30 to 37 weight percent of CaO, 7 to 20 weight percent of SiO2, 35 to 45 weight percent of Al2O3, 5 to 9 weight percent of MgO, and 0.6 to 2.6 weight percent of T.Fe+MnO when the Ruhrstahl-Heraeus (RH) refining treatment begins; 2) performing RH refining, namely deoxidizing by using ferrosilicon when the decarburization of the RH refining is finished, wherein the adding speed of the ferrosilicon is less than or equal to 12.5kg/ton/min; and 3) adding 0.5 to 2.0 kg of calcium alloy into each ton of molten steel for the denaturation control of inclusions after the deoxidization and alloying are performed through the RH refining.

Description

technical field [0001] The invention relates to the production of non-oriented silicon steel, in particular to high-grade non-oriented silicon steel with excellent magnetic properties and a smelting method thereof. Background technique [0002] At present, non-oriented silicon steel is gradually developing towards two poles, that is, the low-grade direction with low price, and the high-grade direction with excellent magnetic properties. High-grade silicon steel refers to the steel type whose finished iron loss is not greater than 4.0W / kg. As far as the high grade is concerned, whether it can effectively reduce the iron loss of the material is its main direction in the future. [0003] It is one of the most effective measures to improve the magnetic properties of high grades to greatly increase the content of Si and Al elements in steel. The reason is that Si and Al elements can significantly increase the resistivity of the material, can effectively reduce the magnetocrysta...

AI Technical Summary

Problems solved by technology

However, under normal circumstances, the density of oxygen and sulfide of rare earths is equivalent to that of molten steel, and it is difficult to remove them during the smelting process.

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