High-yield-strength non-oriented electrical steel plate and manufacturing method thereof

Abstract

Disclosed are a high-yield-strength non-oriented electrical steel plate and a manufacturing method thereof. The manufacturing method includes that firstly, slabs are produced by preprocessing, smelting, vacuum refining and continuous casting of molten iron, and during the finish refining, molten steel is subjected to calcium treatment with CaSi cored wires, 0.5-2.0kg/t of steel is added, killing time of continuous cast molten steel is within 30 minutes, and the ratio of calcium to sulphur in the steel ranges from 1.5 to 2.8 after the calcium treatment; secondly, hot rolling, normalizing, acid pickling and cold rolling processes are performed, wherein rolling with 1-5 passes is performed in a rough rolling section of the hot rolling process, and the initial temperature of slabs is equal to or higher than 1000 DEG C while the rolling speed is equal to or higher than 9m/s in a finish rolling section of the hot rolling process; and thirdly, annealing and insulating coating processes are performed so that finished non-oriented electrical steel plates are obtained, wherein the temperature of a soaking section is controlled to be 800 DEG C-950 DEG C during continuous annealing, and the size of crystal grains of the electrical steel plates ranges from 20 micrometers to 90 micrometers. The quantity of alloy added in the steelmaking process can be reduced obviously so that expenses for alloy are saved greatly. The manufacturing method of the high-yield-strength non-oriented electrical steel plate has the advantages of convenience in operation, simplicity and convenience in control, low cost, control accuracy and the like.

Description

technical field [0001] The invention relates to a non-oriented electrical steel plate and a manufacturing method thereof, in particular to a non-oriented electrical steel plate with high yield strength and a manufacturing method thereof. Specifically include: liquid steel calcium treatment and non-metallic inclusion control technology in the RH refining process, slab heating and hot rolling rough rolling, finishing rolling process control technology, continuous annealing of finished strip steel and product grain control technology . Background technique [0002] In recent years, as people pay more and more attention to energy saving and environmental protection, all kinds of motors, compressors, generators, etc. are gradually developing in the direction of small size, precision and high efficiency. Correspondingly, non-oriented electrical steel sheets as raw materials are required to have good mechanical properties, especially high yield strength, while maintaining high mag...

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Problems solved by technology

[0010] In the first method, due to the gas elements such as C and N, the control precision of the steelmaking process is low, and the improvement effect is not stable.

In addition, when the steel contains high elements such as C and N, it is easy to produce magnetic aging and deteriorate the electromagnetic properties of the steel.

However, when the steel contains high P elements, it is easy to hinder the deep decarburization of molten steel and cause cold and brittle steel strips.

[0011] The second method increases the content of Si, Mn and other elements in the steel, which can effectively reduce the iron loss of the steel, but at the same time it will deteriorate the magnetic induction of the steel.

In addition, increasing the content of Si, Mn and other elements in the steel will easily cause the rolling process to be unstable.

[0012] The latter two methods increase the content of precious metals Cu, Cr, Ni, Nb, V, Ti, Zr and other elements in the steel, which will greatly increase the manufacturing cost of the steel, and the electromagnetic properties of the power frequency magnetic field steel are also very poor.

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