Method for preparing non-oriented silicon steel with excellent magnetic property and high efficiency

Abstract

The invention relates to a method for preparing a non-oriented silicon steel with excellent magnetic property and high efficiency, which comprises the following steps: 1) smelting and casting: wherein the non-oriented silicon steel comprises the following chemical components by weight percentage: less than or equal to 0.0040% of C, 0.1-0.8% of Si, 0.002-1.0% of Al, 0.10%-1.50% of Mn, less than orequal to 0.2% of P, 0.04%-0.08% of Sb, less than or equal to 0.0030% of S, less than or equal to 0.0020% of N, less than or equal to 0.0020% of Ti, balance of iron and inevitable impurity; smelting the above components and casting to casting blank; 2) hot rolling, wherein the slab heating temperature is 1100 DEG C-1150 DEG C, the finishing temperature is 860 DEG C-920 DEG C; rolling and air cooling, wherein the air cooling time (t) is greater than or equal to (2+30*Sb%)s and less than or equal to 7s; reeling at the temperature of 720 DEG C; 3) pickling, cold rolling and rolling with reductionratio of 70-78%; 4) annealing, heating to the temperature of 800-1000 DEG C with speed of greater than or equal to 15 DEG C, insulating for 10s-25s. Under the prerequisite that the magnetic property is ensured, by adding favorable texture elements during the steel-making process, controlling the harmful elements, controlling the air cooling time during the hot rolling process and cooperating by high temperature reeling, the electrical steel production with low cost and high efficiency can be realized.

Description

technical field [0001] The invention relates to a method for manufacturing non-oriented electrical steel, in particular to a method for manufacturing high-efficiency non-oriented silicon steel with excellent magnetic properties, which solves the problems of high normalization cost and long manufacturing cycle for producing high-efficiency non-oriented electrical steel by traditional techniques. Background technique [0002] With the progress of the electric power and electrical industry, electromechanical products are developing towards miniaturization, high precision and high efficiency. The iron core made of ordinary cold-rolled silicon steel sheet is difficult to meet the requirements, and the development of low iron loss and high magnetic induction High-efficiency non-oriented series electrical steel products to replace the current common cold-rolled silicon steel sheet is the main way to reduce the size and weight of electromechanical products, save copper and iron consu...

AI Technical Summary

Problems solved by technology

The problems caused by the normalization of hot-rolled sheets are high manufacturing cost and long manufacturing cycle

The disadvantage is that the hot rolling production process conditions are harsh, the final rolling temperature is high, and the actual production operation and control are very difficult.

[0006] There is also Japanese patent application 2008-260980, which omits annealing for hot-rolled sheets. This patent requires a composition system, which still belongs to a steel type with a relatively high Si content. It requires that the Si content be between 1.5% and 3.5%, (%Si+%Al)≥ 1.9%, during hot rolling, the heating temperature of the slab is very high, 1230-1320°C, and the final rolling temperature is also above 1050°C. At the same time, coiling is required below 700°C. The disadvantage is that the heating temperature of the hot-rolled slab is high. During the hot rolling process, MnS and AlN are easy to be finely dispersed and precipitated, which deteriorates the magnetic properties and is difficult to descale

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