Characterization of microstructure, texture and magnetic properties in twin-roll casting high silicon non-oriented electrical steel

Abstract

An Fe-6.5wt.% Si-0.3wt.% Al as-cast sheet was produced by twin-roll strip casting process, then treated with hot rolling, warm rolling and annealing. A detailed study of the microstructure and texture evolution at different processing stages was carried out by optical microscopy, X-ray diffraction and electron backscattered diffraction analysis. The initial as-cast strip showed strong columnar grains and pronounced <001>//ND texture. The hot rolled & warm rolled sheets were characterized by large amounts of shear bands distributed through the thickness together with strong <110>//RD texture and weak <111>//ND texture. After annealing, detrimental <111>//ND texture almost disappeared while beneficial {001}<210>, {001}<010>, {115}<5 −10 1> and {410} <001> recrystallization textures were formed, thus the magnetic induction of the annealed sheet was significantly improved. The recrystallization texture in the present study could be explained by preferred nucleation and grain growth mechanism.