Development of thin-gauge low iron loss non-oriented silicon steel

Abstract

Microstructure, texture, inclusions and precipitates in Fe-2.97wt%Si non-oriented silicon steel during manufacture were investigated using Scanning Electron Microscopy (SEM), Organic Solvent Electrolysis and Electron Backscattered Diffraction(EBSD)techniques. The P10/400, P15/50 and B50 of thin-gauge non-oriented silicon steel with 0.3 mm in thickness were 13.85 W/kg, 2.38 W/kg and 1.66 T, respectively. Due to annealing of hot rolled band, the size of precipitates increased. The precipitates are mostly located at the grain boundaries in the annealed sheet, the main and average size of the grain-boundary precipitates were in the range of 30 ∼ 500 nm and 63.2 nm, respectively. The pinning force caused by 100 ∼ 300 nm particles at the grain boundaries was the largest, 70 ∼ 100 nm was second. During annealing of hot rolled band, the α*-fiber texture significantly developed and γ-fiber dropped dramatically. The γ-fiber texture and α*-fiber texture composed the main textures of annealed sheet. The texture randomization would give rise to better magnetic properties compared to the γ-fiber.