Development of Non-Oriented Electrical Steel Sheets for Energy Efficient Motor based on Ultra Low Sulfur Technology.

Abstract

The effect of sulfur on the magnetic properties of non-oriented electrical steel sheets was studied. In an ultra low sulfur steel with annealing temperatures ranging from 850°C to 975°C, hysteresis loss is lower than that of a high sulfur steel. However, the hysteresis loss in the ultra low S steel increases with an increase in the final annealing temperature ranging from 975°C to 1050°C. This phenomenon is associated with the precipitation of AlN near the surface of the steel. The nitride forming reaction is accelerated with a decrease in S content. In the ultra low S non-oriented electrical steel sheets, the low core loss was obtained by the reduction of the surface nitriding and the high magnetic flux density was obtained by a reduction of Si and Al content. This steel shows; 1)low hysteresis loss, 2)high magnetic flux density, 3)excellent punching properties and 4)low production cost.