Permanent domain refinement by aluminum deposition.

摘要

The present invention relates to a process for producing permanent domain refinement continuously and at very high line speeds in grain oriented electrical steel having an aluminum nitride inhibitor system. After the final high temperature anneal, the glass film and insulative coating on the surface is removed in narrow bands (grooves or rows of spots). The steel is electroetched to increase the depth of the bands, coated with aluminum by electrophoresis and given a stress relief anneal to bond the aluminum coating to the base metal by diffusion. A localized stress field is induced during cooling which causes domain refinement due to the differential thermal contraction between the aluminum and the base metal.