Non-oriented electrical steel plate with extremely low content of Ti and smelting method for non-oriented electrical steel plate

Abstract

The invention discloses a non-oriented electrical steel plate with extremely low content of Ti and a smelting method for the non-oriented electrical steel plate. The method comprises the following steps of: 1) performing hot metal pretreatment and converter smelting, namely smelting the following chemical components: less than or equal to 0.005 weight percent of C, 0.1 to 1.6 weight percent of Si, 0.1 to 0.6 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, less than or equal to 0.005 weight percent of Al, less than or equal to 0.005 weight percent of N, 0.005 to 0.02 weight percent of O, 0.0002 to 0.001 weight percent of Ti, and the balance of Fe and inevitable inclusions, and reducing the slag takeover by adopting slag stopping operation in a converter so as to ensure that the slag amount of the surfaces of steel ladles is less than or equal to 20kg in each ton of steel after the tapping of the converter is finished; and 2) performing Ruhrstahl-Heraeus (RH) refining, and weakly deoxidizing by using ferroaluminum and ferrosilicon sequentially after the decarburization of the RH refining is finished so as to ensure that the content of free oxygen of weakly deoxidized molten steel is 100 to 300ppm. The production of non-oriented electrical steel plates with extremely low content of Ti is realized by controlling the slag takeover of the tapping process of the converter, weakly deoxidizing by using the ferroaluminum and the ferrosilicon sequentially, and strictly controlling the content of oxygen in steel after the refining is finished.

Description

technical field [0001] The invention relates to a non-oriented electrical steel plate and a smelting method thereof, in particular to a non-oriented electrical steel plate with excellent magnetic properties and extremely low Ti content and a smelting method thereof. Background technique [0002] Ti is a harmful element in electrical steel. During the smelting process, very small amounts of Ti, O, and N elements can combine to form fine inclusions TiO x and TiN et al. These inclusions will significantly reduce the purity of the steel, inhibit the grain growth of the strip steel during heat treatment, and thus greatly reduce the various magnetic properties of the finished strip steel. Based on this, more and more manufacturers put forward strict requirements on the Ti content in electrical steel, with the target being less than or equal to 30ppm, or even 10ppm. [0003] Ti in steel mainly comes from molten iron, slag and ferrosilicon alloy. The interaction relationship bet...

AI Technical Summary

Problems solved by technology

The common disadvantage of the above methods is that it is necessary to reserve time for slag removal and slag removal, thereby prolonging the smelting cycle

In addition, in order to achieve the modification effect of slag, the modification agent added in the smelting process is expensive and the operation process is relatively complicated

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