Roles of Silicon Content and Normalization Temperature on Cold Workability and Recrystallization of High-Grade Non-Oriented Silicon Steel

Abstract

In order to decrease the difficulty of cold workability and study the recrystallization behavior of high-grade non-oriented silicon steel, Si content and normalization temperature were optimized simultaneously. The microstructure and texture of both hot-rolled sheet and normalized annealing sheet presented a gradient distribution. With the decrease in Si content from 3.02% to 2.54% and increase in normalization temperature from 850 °C to 920 °C, Goss texture ({110}<001>) intensity at surface layer and α-fiber (<110>//RD) texture intensity were strengthened, and α-fiber texture gradually turned to α*-fiber ({1 1 h}<1/h 1 2>) in the normalized annealing sheet. Recrystallization ratio and recrystallization grain size were increased both in the hot-rolled sheet and the normalized annealing sheet. The tensile strength and yield strength of normalized annealing sheet were reduced by 65 Mpa, which decreased the cold workability difficulty and improved cold rolling yield. The cold rolled microstructure had wider shear bands which nucleated earlier but recrystallized velocity was slower because of lower cold rolled energy storage during interval recrystallization annealing, resulting in a more heterogeneous grain size distribution in the final annealing sheet.