Comparative analysis of microstructure evolution and magnetic properties in strip-cast vs. Conventionally produced non-grain-oriented electrical steel

Materials research proceedings, vol. 54, pp. 2464–2473

Abstract

Abstract. Non-grain-oriented electrical steels are essential for motors and generators, requiring high magnetic induction and low iron losses. Magnetic properties are influenced by grain size, texture, thickness, and alloying content. Twin-roll casting (TRC) efficiently produces FeSi alloys as near-net strips, eliminating hot rolling and reducing costs, emissions, and energy. Despite its economic and magnetic advantages, understanding TRC’s impact on microstructure and processing into electrical steel remains limited. This study investigates the microstructural evolution and magnetic properties of a Fe–2.9Si–1.35Al alloy processed via TRC (1.6 mm thickness) and further refined through warm rolling, cold rolling, and annealing to produce 0.27 mm NGO steel. Results, including Electron Backscatter Diffraction analysis and single-sheet testing, are compared to conventionally processed hot-strip material. Findings show that TRC with proper processing adjustments enables the production of magnetic properties comparable to industrial materials, though differences arise from grain morphology and texture. Key findings: TRC material exhibits better polarization due to its favorable texture; Loss performance is inferior, likely due to inhomogeneous grain size distribution.

Authors 1

1. Dorothea Czempas corresponding Aachen Institute of Metal Forming

   RWTH Aachen University

   Affiliation as printed

   Institute of Metal Forming, RWTH Aachen University, Germany