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

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 components in 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 0.7-2.5 percent, 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.