Ultralow-nitrogen ultralow-titanium molten steel refining agent and preparation method

Abstract

The invention discloses an ultralow-nitrogen ultralow-titanium molten steel refining agent and a preparation method. The refining agent is prepared from a component A and a component B, the componentA is low-titanium active lime, the component B is one or any combination of industrial aluminum ash, bauxite and calcium slag according to the ingredients and use amounts, the alkalinity R of the refining agent is 3.0-5.0(CaO / SiO2), N is smaller than or equal to 0.02%, and Ti is smaller than or equal to 0.015%. The molten steel refining agent is prepared with an advanced pre-melting vacuum refining process, the ingredients are uniform, inspection is convenient, and mechanical and manual feeding is facilitated. The ultralow-nitrogen ultralow-titanium molten steel refining agent is free of dustand safe and environmentally friendly during use, the content of harmful elements N and Ti is extremely low, storage and transportation are facilitated, the ultralow-nitrogen ultralow-titanium moltensteel refining agent is not easily oxidized by air during use at high temperature, the yield is high, the deoxidization efficiency in slag is high, the speed is high, and the ultralow-nitrogen ultralow-titanium molten steel refining agent is the most ideal high-cleanliness molten steel refining agent.

Description

technical field [0001] The invention belongs to the technical field of molten steel refining agents, and in particular relates to an ultra-low nitrogen and ultra-low titanium molten steel refining agent and a preparation method. Background technique [0002] Ti, O, and N elements have strong affinity. During the steelmaking process, the three elements are easily combined to form fine inclusions such as TiO2, TiN, and TiC. These fine inclusions will reduce the purity of the steel, cause nodules in the continuous casting nozzle, inhibit the grain growth during the annealing process, reduce the favorable texture during the annealing process, and then affect various properties of the steel. Therefore, some special steel types, such as electrical steel, bearing steel, spring steel, etc., have put forward strict requirements on the Ti content in the steel, and hope that the content is ≤30×10 -6 , even ≤10×10 -6 . [0003] Various research data show that TiO in ladle top slag 2...

AI Technical Summary

Problems solved by technology

At the same time, due to the existence of segregated crystallization in molten steel solidification, the concentration of Ti and N at the end of solidification is higher than that of the matrix. If TIN is precipitated at this time, there is still the possibility of aggregation and growth. If large-grained TiN inclusions are generated, it may be harmful to the finished steel. The quality of the greater harm