Bismuth-containing oriented silicon steel smelting method enabling bismuth yield to be not lower than 70%

Abstract

The invention discloses a bismuth-containing oriented silicon steel smelting method enabling the bismuth yield to be not lower than 70%. The method comprises the following steps of, smelting in a conventional converter and tapping into a steel ladle; carrying out RH refining treatment, wherein, the thickness of a slag layer is controlled to be not lower than 45 mm, the slag comprises 25-35 wt% of Al2O3, 40-50 wt% of CaO and 10-15 wt% of MgO, and the temperature of molten steel is controlled to be 1530-1590 DEG C at the end; carrying out sedation after the vacuum refining is finished; adding a bismuth particles and limestone particles mixed container into the molten steel; and protecting casting and post-process production. According to the method, bismuth particles and limestone particles are mixed and added, gas generated by decomposition of limestone in the molten steel can slow down the sinking speed of the bismuth particles, bismuth can be rapidly and uniformly diffused, more importantly, diffusion of the bismuth particles in the molten steel can be strengthened, and finally the ideal effect that the bismuth yield is higher than 70%, specifically 71-75% can be achieved.

Description

technical field [0001] The invention relates to a method for smelting silicon steel, in particular to a method for smelting oriented silicon steel containing bismuth. Background technique [0002] Adding bismuth to alloy steel or stainless steel can improve the cutting performance of steel. By using metal bismuth instead of metal lead and compounding other chemical components, the bismuth-containing free-cutting steel not only has the free-cutting performance of lead-based free-cutting steel, but also is non-toxic and harmless. Bismuth is also a grain boundary segregation element. Adding it to oriented silicon steel can segregate along the grain boundary to hinder the growth of initial grains, and in the later annealing process, it can strengthen the inhibitor's inhibitory force and delay the decomposition of the inhibitor, which can significantly improve the magnetic induction B8 of oriented silicon steel. (B8=1.96~2.00T) and reduce iron loss P17. [0003] Bismuth is a me...

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Problems solved by technology

[0016] The purpose of the present invention is to solve the problem of low yield of bismuth and slow and uneven diffusion of bismuth in the prior art when ladle bismuth is alloyed, and to provide a method that avoids a large amount of volatilization and gasification of bismuth and can quickly diffuse bismuth. Uniform, bismuth-containing oriented silicon steel smelting method that can eventually increase the yield of bismuth element by not less than 70%

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