Abstract: The requirements for electromagnetic properties of silicon steel for high voltage motors are gradually improved as the continuous upgrading of products in downstream electric machinery plant. In this circumstance, BenGang Steel Plates Co. Ltd. has succeeded in developing a nonoriented silicon steel 50BW600 by reasonably designing the chemical composition of the product and its rolling process, and using the cover annealing process to replace the normal process, and improving the continuous annealing system, which were combined with the company's existing technical equipment capacity. The developed nonoriented silicon steel 50BW600 accords with expected target on the electromagnetic performance, with the iron loss less than 3.7 W/kg and the magnetic induction higher than 1.68 T, meeting the supply standard, and enhancing the market competitiveness of the product.

Key words: high voltage motor, cover annealing, electromagnetic performance