High-strength non-oriented electrical steel with high magnetic induction and manufacturing method thereof

Abstract

High-strength non-oriented electrical steel with high magnetic induction and a manufacturing method thereof. The method comprises the following steps of: 1) smelting and casting, wherein the electrical steel comprises the following components by weight: not more than 0.0040% of C, 2.50-4.00% of Si, 0.20%-0.80% of Al, 1.0-8.0% of Cr, 0.5-5.0% of Ni, not more than 0.50% of Mn, not more than 0.30% of P, not more than 0.0020% of S, not more than 0.0030% of N, not more than 0.0030% of Ti, not more than 0.010% of Nb, not more than 0.010% of V, not more than 0.010% of C+S+N+Ti, and the balance of Fe; smelting, RH vacuum treatment, casting; 2) hot rolling; 3) normalization at a temperature of 850-950 DEG C for 0.5-3 min, slow cooling to 650-750 DEG C with a speed of 5-15 DEG C / s, rapid cooling to below 100 DEG C with a speed of 20-70 DEG C; 4) pickling and cold rolling with a total reduction rate of not less than 70%; 5) annealing at 800-1000 DEG C for 5-60 seconds, slow cooling to 650-750 DEG C with a speed of 3-10 DEG C / s, rapid cooling to below 100 DEG C with a speed of 20-70 DEG C. The method of the invention produces non-oriented electrical steel with both high strength and high-efficient magnetic properties without the increase of manufacturing difficulties.

Description

Technical field [0001] The present invention relates to the field of electrical steel manufacturing, in particular to a high-strength non-oriented electrical steel with high magnetic induction and a manufacturing method thereof suitable for high starting torque and impact resistance required by electric vehicle motors and high-speed running motors. Solid solution strengthening elements such as Ni, Cr, etc., control C, N, S, Ti and other harmful elements to magnetic properties, ensure the magnetic properties of electrical steel, and improve the yield strength of electrical steel. At the same time, the hot-rolled sheet is properly normalized annealing Treatment improves the magnetic induction of the product. Background technique [0002] With the depletion of non-renewable resources such as petroleum and coal, the environmental greenhouse effect is becoming more and more serious. Electric vehicles and hybrid vehicles have been paid more and more attention as low-pollution and highl...

AI Technical Summary

Problems solved by technology

However, such products have poor toughness and plasticity, are brittle, and have low magnetic induction. They are not suitable for high-speed motors such as electric vehicle motors. It is necessary to develop non-oriented electrical steel with high strength and high magnetic induction.

[0004] Chinese Patent No. 1863934 discloses a "high-strength electrical steel sheet and its processed parts and their manufacturing method", its composition adopts the addition of strengthening elements such as Mn and Cu to improve the yield strength and tensile strength of the electrical steel sheet, and its shortcomings Because cold rolling is difficult in the process of manufacturing products according to this method, it also affects the magnetic properties of the electromagnetic steel sheet, and the magnetic induction intensity of the obtained electromagnetic steel sheet is relatively low; Cooling to medium temperature, this process will cause a large internal stress inside the strip steel, which will have an adverse effect on the shape of the strip steel plate, and also affect the magnetic properties and fatigue resistance of the product; in addition, the patent requires that during the cooling process of cold rolling annealing, Keep hardening in the middle temperature section for a long period of time, which is not conducive to the realization of general industrial annealing units

This method will generate strong stress in the strip steel, which will seriously affect the shape of the strip steel plate and the magnetic properties of the product, which is not conducive to the application in actual industrial production.

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