A production method of grain-oriented silicon steel with low inclusion defect rate and high magnetic induction

Abstract

The invention relates to a production method of high-magnetic-induction-orientated silicon steel with the low inclusion defect rate. The production method comprises the steps that smelting: argon blowing is conducted in the whole process of converter smelting; at the after-furnace end point of a converter, C is controlled to be less than or equal to 0.040%, P is controlled to be less than or equalto 0.011%, and S is controlled to be less than or equal to 0.005%; slag in the converting process has the alkalinity of 3.0-3.5 and the thickness less than or equal to 80mm; the slag is pushed off when steel tapping is finished; calculating the width of a liquid phase line of actual smelting components of high-magnetic-induction-orientated silicon steel; utilizing the calculated liquid phase linewidth result, controlling the superheat degree of molten steel in a tundish and controlling the temperature in the solidification process to be within 90-130 DEG C; and conducting electromagnetic stirring in the continuous casting process, conducting hot charging on a casting blank after continuous casting and controlling the temperature of the casting blank to be greater than or equal to 700 DEGC. The production method has the advantages that the width of the liquid phase line of the smelting components can be quickly and accurately calculated; the continuous casting technological parameters are reasonably designed according to the calculation result; the quantity of inclusions in a steel plate is effectively controlled; the finished steel rate is increased; the cost is saved; and wasteis reduced.

Description

technical field [0001] The invention relates to a production method of oriented silicon steel with low inclusion defect rate and high magnetic induction. Background technique [0002] Oriented silicon steel is divided into two categories according to the level of magnetic induction: general oriented silicon steel CGO, magnetic induction < 1.88T; high magnetic induction oriented silicon steel HGO, magnetic induction ≥ 1.88T. High magnetic induction oriented silicon steel has high magnetic induction, low iron loss, and the manufactured transformer has the characteristics of low noise. It is widely used in the manufacture of large-capacity power transformers with voltage levels above 220KV and high-efficiency and energy-saving distribution transformer cores. With the improvement of requirements, the scope of application is getting wider and wider. [0003] High magnetic induction oriented silicon steel was first invented by Japan's Nippon Steel Corporation in the 1960s. The...

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Problems solved by technology

At present, large oriented silicon steel manufacturers in my country also use empirical formulas to calculate the liquidus temperature, which cannot accurately calculate the liquidus width, which directly leads to fuzzy control of the solidification process. When the liquidus line width of the actual casting composition is narrow At that time, using the pouring technology near the liquidus temperature, the result is that the viscosity of the molten steel is high, and the inclusions are not easy to float up. As a result, there are a large number of inclusions visible to the naked eye from the surface of the hot-rolled sheet and the normalized sheet to the surface of the finished sheet, and there are many defects in the finished product. Low material rate, resulting in a lot of waste

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