Microstructure and texture evolution during normalization of high-grade 3%Si non-oriented electrical steel

The industrially produced hot-rolled plate of 3%Si non-oriented silicon steel as the raw material, was used for normalization treatment. The microstructure and texture were studied using EBSD technology. The results show that the surface layer of the normalized sheet always consists of recrystallized grains, and the grain size increases with increase the holding time. As the holding time increases, the evolution path of the shear texture on the surface layer is: {110}<114>→ {110}<113>→{110}<001>→{441}<118>. The copper-type texture consistently aggregates around {112}<111>∼{113}<332>. Before holding at 950 °C for 50 s, the core of the normalized sheet does not undergo complete recrystallization. Complete recrystallization occurs after holding for 60 s, with an average grain size of 69.95µm. As the holding time continues to increase, the average grain size also increases. Before recrystallization occurs in the core of the normalized sheet, the texture is mainly a strong α-fiber texture, concentrated around {112}<110> ∼ {114}<110>, with a weaker γ-texture also present. After recrystallization, the α*-fiber texture gradually develops into a core texture. The α*-fiber texture is concentrated around {114}<481>, and its orientation nucleation sites can be divided into two categories: the first type of nucleation site is within the banded structures of the α-fiber texture {114}<110> and {113}<110>; the second type of nucleation site is at the grain boundaries of {111}<112>.