Investigation on the Early Stages of Growth of Secondary Grains in a Grain Oriented Silicon Steel

Abstract

A sequence of cyclic annealing experiments was performed to trace the growth of secondary grains after primary recrystallization in a two-pass cold rolled Fe-3.5%Si steel. By using electron backscattered diffraction (EBSD), the development of grain growth and texture in the early stages of secondary growth in as-received and annealed samples was examined. Annealing was performed at 900°C for 3, 6 and 15min. During the early stages of secondary growth, it was observed that Goss grains and other oriented grains can grow at the expense of their surrounding matrix grains. This growth is likely to be determined by particle dissolution at their boundaries which, hence, affects their ability to break away from pinning. It is shown that the presence of Σ5 and Σ9 CSL boundaries that surround Goss grains, size advantage in the as-received sample, texture sharpness and the presence of Goss grain colonies do not guarantee Goss grains to successfully grow at this stage of annealing.