Non-oriented electrical steel with excellent magnetic properties of rm≥600mpa and its production method

Abstract

The invention discloses non-oriented electrical steel with excellent magnetic performance and Rm not smaller than 600 MPa, wherein the non-oriented electrical steel is composed of the following components by weight percent: 2.5-3.5% of Si, 0.1-1.0% of Mn, not more than 1.0% of Ni and Al, not larger than 0.005% of N, not larger than 0.015% of S, not larger than 0.003% of C and not larger than 0.05% of P; the production steps are as follows: smelting and continuously casting a bloom; heating the continuously cast bloom; hot rolling; coiling; normalizing; pickling and cold rolling; continuous annealing; and naturally cooling to the room temperature for future use. The mechanical properties and magnetic performance of the non-oriented electrical steel disclosed by the invention can simultaneously satisfy the requirements of motor steel, namely, Rm is not smaller than 600 MPa, Rel is not smaller than 500 MPa, P1.0 / 400 is not larger than 17 W / kg, B 5000 is not smaller than 1.66 T, and stators and rotors are processed by the same electromagnetic steel plate to reduce the time and material costs.

Description

technical field [0001] The invention relates to a non-oriented electrical steel and a production method thereof, in particular to a non-oriented electrical steel with excellent magnetic properties of Rm≥600MPa and a production method thereof. Background technique [0002] In recent years, global environmental problems have become increasingly prominent. Many energy-saving fields are promoting energy-saving products. Environmental response technologies are constantly developing. The automotive field is no exception. Low emissions and fuel consumption reduction technologies have made great progress. The fields of electric vehicles and hybrid electric vehicles are very prominent examples in the field of energy saving and emission reduction, and the performance of vehicle drive motors directly affects the performance of these electric vehicles. [0003] The iron core of the drive motor mostly uses permanent magnets, and the stator and rotor are formed together. Recently, the IP...

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Problems solved by technology

[0010] Usually, the means to reduce iron loss include adding appropriate alloying elements to promote the development of recrystallization structure, or using appropriate technological means to obtain a sufficiently large grain size of the finished product, thereby reducing hysteresis loss, but the addition of many alloying elements will reduce the magnetic field. Inductive strength, which leads to a decrease in motor torque, on the other hand, promotes the development of recrystallized structure and reduces the strength of the finished product, and the use of appropriate technological means to obtain a sufficiently large grain size of the finished product will also reduce the strength of the finished product

Japanese Patent Laid-Open No. 2010-24509 discloses a non-oriented electrical steel sheet with excellent strength and magnetic properties developed by Nippon Steel. Ni and Cu are added in a certain proportion to achieve the effect of improving magnetic properties, magnetic induction and strength. The Al content The highest can reach more than 3.0%. Cu will precipitate fine ε-Cu second phase particles in the hot rolling process, which will hinder the growth of grains in the recrystallization process and deteriorate the magnetic properties. The Al content in molten steel is high. It is easy to form nodules, the surface of the slab is easy to scar, and the surface of the finished product has many defects. Al is also easy to produce an inner oxide layer and an inner nitride layer during annealing. In addition, the patent also adds 0.01%-0.10% of Sn, and the melting point of Sn is higher than that of Al. Low, easy to produce nodules on the surface of the steel plate during the annealing process, and the addition also increases the cost of the alloy

Finally, the patent only gives the yield strength, elongation and eddy current loss data, but does not mention the total loss and magnetic induction level. Japanese Patent Laid-Open No. 2011-89204 discloses a non-oriented electrical steel sheet for rotors developed by Sumitomo Metal The manufacturing method, which controls the recrystallization ratio during the annealing process by adding Nb, a large number of fine Nb(C,N) particles precipitated during the hot rolling process, so as to achieve the effect of precipitation strengthening, and the yield strength of the 0.35mm finished product reaches 659MPa, the tensile strength reaches 768MPa, but if the recrystallization ratio is too low, the magnetic properties will deteriorate, especially the iron loss will increase significantly, and the 0.35mm finished high-frequency iron loss P 1.0 / 400 Up to 46W / kg, so it is only suitable for rotor material

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