Method of producing stable magnetic domain refinement of electrical steels by metallic contaminants

摘要

A method is provided for refining the magnetic domain wall spacing of grain-oriented silicon steel sheet having an insulation base coating thereon by removing portions of the base coating to expose a line pattern of the underlying silicon steel substantially transverse to the rolling direction of the steel, applying a metallic contaminant to the steel, the exposed steel being free of thermal and plastic stresses, and thereafter annealing the steel and contaminant thereon at time and temperatures of about 1400 DEG F. or more in a protective atmosphere to diffuse sufficient and controlled amounts of the comtaninant into the steel to produce a permanent pore stable up to 2100 DEG F. to effect heat resistant domain refinement and reduce core loss.