Method for producing oriented silicon steel with excellent magnetic property

Abstract

A method for manufacturing a grain-oriented silicon steel having excellent magnetic performance, comprising steps as follows 1) conventionally melting and casting into a steel blank; 2) heating the steel blank and hot rolling the same into a strip of steel; 3)normalizing process; carrying out the normalizing process having two stages, wherein the strip is firstly heated to 1100ˆ¼1200°C, then cooled to 900ˆ¼1000 °C within 50-200s; and next, the strip is rapidly cooled in water having a temperature of 10ˆ¼100; in this period, a tension force is applied to the strip of steel, the strip of steel in the temperature range of 900°Cˆ¼500°C has a stress of 1ˆ¼200N / mm 2 ; 4)cold rolling, i.e. carrying out a primary cold rolling, or a double cold rolling with intermediate annealing; 5)carrying out primary recrystallizing annealing, then coating an annealing separator, whose main composition is MgO, to carry out final product annealing comprising secondary recrystallizing annealing and purifying annealing. The invention optimizes the content and distribution of martensite in the steel plate after normalization by adjusting the tension force applied to the steel plate while normalization transformation, so as to make the content of martensite in the range ensuring a better magnetic performance of the final product and to optimize the magnetic performance of final products.

Description

technical field [0001] The invention relates to a method for producing oriented silicon steel, in particular to a method for producing oriented silicon steel with excellent magnetic properties. Background technique [0002] Grain-oriented silicon steel is an important soft magnetic alloy indispensable to electric power, electronics and military industries, and is mainly used as transformer core, generator and large motor, etc. Excellent magnetic properties are required, especially low iron loss. [0003] Oriented silicon steel uses secondary recrystallization technology to make Goss texture (Goss texture: {110} crystal plane parallel to rolling surface, <001> crystal direction parallel to rolling direction) to undergo abnormal grain growth and annex other orientation grains. After graining, excellent rolling direction magnetic properties are obtained. [0004] The traditional production method of high magnetic induction grain-oriented silicon steel is as follows: ...

AI Technical Summary

Problems solved by technology

[0007] 1. The heating temperature is high, and the burning loss of the slab is large;

[0008] 2. The heating furnace needs to be repaired frequently, and the production efficiency is low;

[0009] 3. The hot-rolling temperature is high, and the hot-rolled edge cracks are large;

The disadvantage of this patent is that it is difficult to realize the uniformity of cooling rate in the thickness direction of the plate, which leads to the inhomogeneous distribution of martensite in the direction of plate thickness; also because of the inhomogeneity, it is difficult to realize the effective distribution of martensite control

Moreover, water is used to control the cooling rate from 700 to 900°C to room temperature. First, it is easily limited by site conditions, such as air temperature, nozzle damage or blockage, which may lead to instability of cooling rate; Human factors are large, and it is difficult to achieve precise control, making it difficult to achieve fine-tuning of cooling speed

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