Review of the types, properties, advantages, and latest developments in insulating coatings on nonoriented electrical steels

Continuous efforts are directed at developing improved electrical steels with lower iron losses for energy-efficient transformers and motors. The core losses can be limited by insulating coatings, and various types of coatings have been developed for application to both fully processed and semiprocessed electrical steels. The primary and secondary properties of such coatings and the inefficacy in ultimately improving machine performance are discussed. This insight is vital to design engineers in making the correct decision on coating requirements. The latest advances made in electrical steel coating technology at European Electrical Steels (EES) are also discussed.