Boron-containing steel production method for reducing steel ladle lining refractory consumption

Abstract

The invention relates to a boron-containing steel production method for reducing steel ladle lining refractory consumption, and belongs to the technical field of steel production. The technical scheme of the process flow comprises converter blowing, LF refining, ferroboron alloying and molding protection; each process is controlled as follows: converter blowing adopts hot metal containing 0.15-0.20% of Ti, steel tapping adopts Si-Al-Ba and Al-Mn-Ti-Mg to deoxidize, the whole operation process of steel ladle is protected by a protective cover, refined submerged arc slag is added into an LF Furnace adopting micro positive pressure operation, alloyed ferroboron is added before performing soft blowing, and crystallizer casting powder containing 5-10 % of TiO2 and 4-8% of B2O3 is adopted in the process of molten steel molding. By adopting the method, the yield of boron is improved and stabilized, and the magnesia steel ladle lining consumption rate is effectively reduced, so that the comprehensive smelting cost is reduced, and the service life of the steel ladle refractory material is prolonged by 8-12 times per bag; the lining erosion degree is reduced to form a reasonable bag throwing and injecting system, and the number of on-line baking steel ladles is reduced, so that the cost of gas consumption of 1 ton of steel is reduced by 13.3-17.8 Yuan; the yield of casting blank boron is improved by 8-10%; comprehensive benefit of 315.05 million each year is achieved.

Description

technical field [0001] The invention relates to a boron-containing steel production method for reducing the consumption of refractory materials in the ladle lining, and belongs to the technical field of steelmaking production. Background technique [0002] Boron microalloying can improve the hardenability of steel and reduce the yield strength of steel; adding an appropriate amount of boron can also reduce the melting point of inclusions in steel and achieve the plasticization requirements of inclusions. However, due to the presence of a certain amount of B 2 o 3 , the performance of slag has changed greatly, and its mechanism of action with refractory materials and the control method of refractory material erosion are also worthy of attention. by MgO-B 2 o 3 It can be seen from the phase diagram that B 2 o 3 Easily react with MgO to form MgO·B 2 o 3 , 2MgO·B 2 o 3 , 3MgO·B 2 o 3 compounds with low melting points. The research on the reaction between boron-conta...

AI Technical Summary

Problems solved by technology

In summary, with the increase of temperature, the increase of B2O3 content in slag, the decrease of MgO content and the decrease of basicity, B2O The permeability and reactivity of 3 to the MgO lining are enhanced, and the loss rate is greatly increased

[0003]Different researchers mentioned methods such as using vacuum smelting (such as Chinese patent 200810015497.9) and spraying boron-containing powder at the long nozzle of the tundish (such as Chinese patent 200910011914.7). This type of method not only significantly increases the yield of boron (up to 70~90%), but also minimizes the B2O3 content in the slag without the presence of a ladle The loss rate of the inner lining increases, but there are problems such as unstable boron yield, high cost of vacuum treatment, serious oxidation of molten steel at the long nozzle of the tundish, etc.

Background Art In the process, aluminum is usually used for deoxidation first, then vanadium, zirconium, titanium, etc. are used for nitrogen fixation, and finally boron-iron or boron cored wire alloying is used for three-step operation. By controlling the oxygen and nitrogen of molten steel to improve and stabilize the yield of boron, the advantage is that boron alloying increases the content of B2O3 in the slag at the end of refining Limited, the loss of ladle refractory materials is not significant, the disadvantage is that the consumption of denitrification alloys such as titanium, vanadium, zirconium increases the cost of smelting, etc.

Chinese patent 200910115090.8 only relies on controlling the contents of Als and T[O] in molten steel during LF refining, that is, a higher boron yield can be achieved without a separate nitrogen fixation treatment. Since boron alloying is mostly in the white slag period, the yield of boron The fluctuation is large, and at the same time, the contact time between the boron-containing slag and the ladle lining is long, and the loss of refractory materials of the ladle is high

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