Influence of turning on the magnetic properties of electrical steel in the production of electrical machines

This paper presents a method to determine the influence of a turning process on the magnetic properties of non-orientated electrical steel sheets. This is done by measuring the magnetization curve of ring specimens by using them as a kind of transformer core. The magnetization curve can be calculated by measuring the current on the primary side and the voltage on the secondary side which has opened clamps. To determine the influence of the turning process two approaches are considered. The first one compares two turned ring specimens of which one consists of two concentric rings so that the cutting length is doubled. The second approach compares a turned ring specimen with a laser and a water jet cut specimen. The measurements have shown that turning has only a slight influence on the magnetic properties. It is about the same as water jet cutting and less than laser cutting for low field strengths.