Kinetics of columnar abnormal grain growth in low-Si non-oriented electrical steel

Abstract

Decarburising annealing in the two-phase region is a well-known method to provide abnormal columnar grain growth in non-oriented electrical steel. Previous investigations have revealed that columnar-grained material produced in this way has an increased intensity of the “random cube” {1 0 0}〈0 v w 〉 and reduced {1 1 1}〈 u v w 〉 deformation texture components in comparison with the same material with a typical equiaxed microstructure. In the present paper, the kinetics of the microstructure and texture development during the columnar grain growth is investigated by means of electron backscatter diffraction with emphasis on the early stages of the process. It has been found that texture changes reflect the character of the columnar grain growth when with further propagation of the columnar grains from the surface to the midplane the global texture becomes similar to the one of the near surface region in primary recrystallised material.