Non-oriented electrical steel for variable frequency motor and production method thereof

Abstract

The invention relates to non-oriented electrical steel for a variable frequency motor and a production method thereof, aiming to overcome the defects of traditional non-oriented electrical steel which has high strength and poor toughness and can not meet the requirement of the variable frequency motor and complex process. The non-oriented electrical steel comprises the flowing chemical componentsin percentage by weight: 0.001-0.015 percent of C, 0.3-0.9 percent of Mn, 0.4-1.6 percent of Cr, 0.1-1.2 percent of Al, 0.9-1.6 percent of Si, no more than 0.08 percent of P, no more than 0.015 percent of S, no more than 0.008 percent of N and the balance of Fe and residue, wherein the sum of the weight percent of Si and Al is 1.4-2.2 percent, the sum of the weight percent of Cr and Mn is 0.7-2.5percent, and Cr / Mn is 0.9-2.0. The production method comprises the following steps of: smelting by using a clean steel process and continuously casting to form a billet; heating the billet; roughly rolling; finish rolling, and controlling the accumulated percentage of reduction of former four passes to be 80-95 percent; reeling; naturally cooling to the room temperature; washing with acid; cold rolling; decarbonizing; soaking; cooling according to conventional method, coating and finishing. The invention has the advantages of simple process, low iron loss at low frequency and power frequency,lower iron loss at high frequency, higher magnetic induction as well as good corrosion resistance and stamping property.

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 for frequency conversion motors and a production method thereof, which is mainly used for manufacturing iron cores of frequency conversion motors such as refrigerator air conditioner compressors and servo control motors. Background technique [0002] With the development of electrical technology, the motor is required to have a high starting torque under low starting current (small excitation current), but for ordinary induction motors, high starting torque and low starting current are contradictory. According to the principle of the motor, low starting current When the starting torque is small, it is difficult to start. Frequency conversion technology can solve this contradiction, and the magnetization frequency can be increased when high starting torque is required under low starting current. In addition, the adv...

AI Technical Summary

Problems solved by technology

In fact, the high-frequency magnetic properties and low-field and high-field magnetic properties of silicon steel with better power frequency magnetic properties are not necessarily good.

In addition, there are conflicting problems between the various indicators of magnetic properties and between magnetic properties and mechanical properties: silicon steel with high magnetic induction generally has higher iron loss and lower strength, and low iron loss silicon steel has lower magnetic induction and strength. High but poor toughness

[0014] In the production process of traditional ordinary non-oriented electrical steel medium and high grades, the normalization furnace is often used. The disadvantages are that the process procedure is complicated, the process energy consumption is high, the production efficiency is low, and the yield is not high, which leads to an increase in production costs.

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