IRON LOSS OF GRAIN-SIZE CONTROLLED VERY THIN GRAIN-ORIENTED SILICON STEELS

Very thin (less than 100 mu m) grain-oriented silicon steels are known to have lower iron loss than iron-based amorphous materials. It is po ssible to reduce the iron loss of very thin grain-oriented silicon ste els further by applying new magnetic domain refining techniques. One m ethod for magnetic domain refining is to control the grain size. We ob served the magnetic domains and measured the iron loss of very thin gr ain-oriented silicon steels that had various grain sizes, We controlle d grain size in samples to be from 0.25 mm to 2.3 mm without changing B-8. This experiment shows that the magnetic domain width can be made narrower by decreasing the grain size, which reduces the eddy current losses. On the other hand, samples with larger grain size have tower H c and lower hysteresis losses. Therefore there is an. optimum grain si ze for the lowest iron loss of very thin grain-oriented silicon steels .