| Abstract Scope |
High-alloy, non-oriented, electrical steels with Silicon, Aluminum and Manganese concentrations over 4.5 wt.% collectively, are the material of choice for high-efficiency motors. These elements, used to increase the resistivity of the steel and lower core loss are also prone to oxidation, and in some cases nitridation, during annealing processes. Surface oxides and nitrides on the strip are known to adversely affect final magnetic properties and other surface sensitive properties such as insulating coating adhesion. Variations in coating adhesion, though less well characterized than effects on magnetic properties, is no less important given the proliferation of bonded lamination stacks in traction motor cores. Therefore, this presentation aims to better elucidate influences of annealing atmosphere composition (H<sub>2</sub>, N<sub>2</sub>, and Dewpoint) in the Annealing and Coating Line (ACL) where final primary recrystallization occurs on key magnetic properties and other performance factors affected by strip surface conditions. |