A PROCESS FOR MANUFACTURE OF MAGNETIC MATERIAL HAVING IMPROVED CORE LOSS BY LOCAL HEAT TREATMENT OF ELECTRICAL STEEL

摘要

A process for improving the core loss of magnetic materials of the type having a plurality of magnetic domains and which may have an insulative coating such as a mill glass, an applied coating, or both. The magnetic material is subjected to a local heat treatment employing radio frequency induction heating, radio frequency resistance heating, or electron beam resistance heating to induce artificial boundaries. Thereafter, the magnetic material is subjected to an annealing treatment.