Columnar grain growth during annealing prior to cold rolling of non-oriented electrical steels

[Display omitted] •Intercritical annealing modifies grain structure and texture of hot-rolled bands.•Decarburization and isothermal γ-Fe → α-Fe transformation assist columnar grain growth.•Decarburization rate affects the driving force needed for columnar grain growth.•Bain and Kurdjumov-Sachs correspondence relationships may explain changes in texture.•Deformation texture is also modified: α and γ fibers weaken and θ-fibre strengthens. The present research reports the microstructural factors that favor the development of columnar grains during annealing prior to cold rolling (APCR). Results show that decarburization of steel has a strong effect on phase transformations, grain structure and crystallographic texture. Annealing at 850 °C (two-phase field) promotes the development of columnar-grained microstructures with orientations close to the ideal cube texture. Higher annealing temperatures within the intercritical region, results in a mixture of columnar + equiaxial grains (875 °C) or completely equiaxial-grained microstructures (900 °C). Annealing at temperatures within the single ferrite (700 °C, 750 °C) or austenite (950 °C, 1050 °C) phase fields does not promote the development of columnar grains. In these cases, annealing promotes the development of equiaxial grains with rotated cube texture and orientations along the γ-fibre. Changes in texture produced by APCR are consistent with the Bain and Kurdjumov-Sachs correspondence relationships and occur according to oriented nucleation and selective growth mechanisms depending on the characteristics of decarburization.