Correlation of aluminum content, inclusion structure, and core loss of nonoriented electrical steels

The addition of 0.3%–0.6% aluminum is widely used to reduce the core loss of nonoriented silicon steels. The core loss reduction due to Al was found much more intensive than expected. It was suggested that the effect of Al can be mainly connected to the change of inclusion structure. In this work silicon steel samples containing different amounts of Al (0.008–0.49 wt. %) were investigated by scanning and transmission electron microscopy, and the inclusion structures were analyzed.