Method for smelting low-titanium steel by electric furnace under condition of high melted iron ratio

Abstract

The invention provides a method for smelting low-titanium steel by an electric furnace under the condition of a high melted iron ratio. The method comprises the sequentially-performed steps of (1), furnace burden condition and charging system determining; (2), melted iron pretreating; (3), electric furnace steelmaking process controlling; (4), steel tapping; (5), LF furnace refining; (6), VD furnace refining; and (7), casting. According to the method for smelting the low-titanium steel by the electric furnace under the condition of the high melted iron ratio, by analyzing the source of the titanium element in the steel, the amount of titanium brought in the steel is controlled in a targeted mode, and the low titanium content in the steel is realized by utilizing the titanium-oxygen reaction in the smelting process through appropriate increase in the slag quantity and other measures. The method for smelting the low-titanium steel by the electric furnace under the condition of the high melted iron ratio is suitable for production of all kinds of low-titanium steel, the proportion of melted iron is not lower than 60wt%, the mass percentage content of Ti in the molten steel at the electric furnace smelting end point is not larger than 0.0005%, and the titanium content in finished steel is not larger than 0.0015wt%.

Description

technical field [0001] The invention relates to the technical field of steelmaking, in particular to a method for smelting low-titanium steel in an electric furnace under the condition of high iron-water ratio. Background technique [0002] Titanium has a very strong affinity with nitrogen, oxygen and carbon in steel. When the molten steel is completely deoxidized, titanium in the steel preferentially combines with nitrogen in the steel to form TiN. TiN in the steel is a hard and brittle inclusion. , has obvious geometric edges and corners, is irregularly distributed in the steel matrix and has a different thermal expansion coefficient from the metal matrix, and is prone to stress concentration and fatigue cracks when subjected to external deformation force or heat treatment. The inclusion of TiN in steel such as bearing steel is more likely to cause defects such as partial shedding when the bearing is rolling, which affects the fatigue life. Therefore, for steel types such...

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Problems solved by technology

[0004] At present, when producing low-titanium steel, iron and steel enterprises mainly focus on the selection of raw and auxiliary materials with low titanium content, high oxygen potential in the primary smelting furnace, large amount of slag in the refining furnace, and slag removal treatment. However, the oxygen supply intensity of the electric furnace and the stirring The capacity is weaker than that of the converter, and it is very difficult to produce steel grades with a titanium content of no more than 0.0015wt% under the high-hot metal ratio electric furnace process conditions. It is difficult to produce a titanium content that meets the requirements of the steel grades using existing production methods