Effect of Heating Rate of Short-Time Heat Treatment by using Low-Frequency Induction Heating on Magnetic Properties of Semi-Processed Electrical Steel Sheets

In order to investigate effect of heating rate of short-time heat treatment using low-frequency induction heating on the magnetic properties of semi-processed electromagnetic steel sheets, magnetic properties of ring core samples were measured and the grain sizes were also measured by using a scanning electron microscopy. The results of the magnetic property measurements showed that the iron loss decreased at lower heating rate and higher attained temperature. The grain size measurements revealed that the secondary recrystallization was suppressed at higher heating rate. Furthermore, the eddy current loss and the hysteresis loss tended to increase and decrease, respectively, as the average grain size increased.