A method for synchronous desulfurization of molten steel and slag in rh vacuum furnace for non-oriented silicon steel

Abstract

The invention discloses a method for synchronously desulphurizing molten steel and slag of a non-oriented silicon steel RH vacuum oven. The method mainly comprises the following steps: molten steel pretreatment (a KR method), converter smelting and RH vacuum refining, wherein the RH vacuum refining comprises the steps of carrying out vacuumizing and decarbonization on RH entering a station, after the decarbonization of RH is finished, adding a low-carbon steel slag surface deoxidant into the surface of the steel slag, simultaneously carrying out steel ladle bottom blowing to promote the reduction of the low-carbon steel slag surface deoxidant to steel ladle slag, after the low-carbon steel slag surface deoxidant is added, adding metal aluminum, silicon iron and manganese metal into molten steel, carrying out deoxygenation and alloying, carrying out circular processing for 4-7 minutes, adding a desulphurizing agent in different stages, simultaneously adjusting the steel ladle bottom blowing flow to promote slag-metal reaction to realize desulphurization, carrying out desulphurizing molten steel by virtue of the desulphurizing agent and the steel ladle slag so as to improve the desulphurization efficiency, after the desulphurization is finished, carrying out clean circulation for more than 8 minutes, and carrying out vacuum breaking and steel tapping. The sulfur content of an RH end point is less than 30ppm, and the standardized rate is increased from original about 22% to 95% or above.

Description

technical field [0001] This application relates to the technical field of refining and desulfurization of molten steel outside the furnace, in particular to a method for synchronous desulfurization of molten steel and slag in a non-oriented silicon steel RH vacuum furnace. Background technique [0002] The main purpose of cold-rolled non-oriented silicon steel sheet is for the manufacture of generators, so it is also called cold-rolled electrical silicon steel. Its silicon content is 0.5% to 3.0%. After cold rolling, the finished product thickness is mostly 0.35mm and 0.5mm thick steel strip. Due to the relatively low technical barriers of non-oriented silicon steel, there are many production capacities under construction and proposed. The silicon steel market competition is intensifying. At the same time, from the point of view of energy saving, the trend of technological development is to improve the efficiency of electrical equipment. One of the main means is to improve ...

AI Technical Summary

Problems solved by technology

[0007] 2) During the smelting process of the converter, a large amount of sulfur is brought into by adding steel scrap and slagging materials, coupled with the oxidizing atmosphere in the converter, resulting in a large amount of sulfur returning to the molten steel after smelting

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