Origin of Goss (110)〈001〉 Grains in Hot-Worked Grain-Oriented Steel

Abstract

This study involved hot working, mimicking the first strand of a compact strip production, of grain-oriented (GO) and non-grain-oriented (NGO) electrical steel. The as-cast microstructures, between the grades, were similar: large (~ 550 μm average diameter and 1 to 7 mm length) columnar grains with ND//〈001〉 fiber texture. However, the developments in hot-worked microstructures were remarkably different. Firstly, the GO had higher carbon (0.06 vs 0.003 weight pct)—which led to the presence of austenite phase at the hot working temperatures. The GO also showed dynamic recrystallization (DRx) and the presence of Goss (110)〈001〉 grains in the hot-worked state. These were absent in the NGO. Further, the majority (~ 95 pct) of the Goss grains, in the hot-worked GO, originated from dynamic recrystallization (DRx) in the ferrite phase, surrounding the harder prior austenite regions. This study thus identified DRx by particle-stimulated nucleation as the primary source of Goss orientation in the hot-worked GO.