High silicon non-oriented electrical steel sheets fabricated by hot dipping and diffusion annealing

High silicon (∼6.5 wt%) non-oriented electrical steel sheets were produced by hot dipping cold rolled 3.5 wt% Si steel sheets into a hypoeutectic Al-8 wt% Si melt followed by diffusion annealing. The microstructure and element diffusion of the processed sheets were characterized and simulated. It is demonstrated that the Al and Si contents across the sheet thickness are largely increased, and the elements are fairly uniformly distributed, which significantly reduced the core loss of the steel sheets, i.e., close to that of the 6.5 wt% silicon steel manufactured by chemical vapor deposition. This manufacturing route features low capital investment and easy process control and has great potential to become a viable technique to produce high silicon electrical steels.