Berlin 2012 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 21: Microstructure and Phase Transformations II
MM 21.4: Vortrag
Dienstag, 27. März 2012, 11:00–11:15, H 0106
Abnormal grain growth of Goss grains in grain-oriented electrical steel — •Wei Guo1 and Wei-min Mao2 — 1Department of Microstructure Physics and Alloy Design,Max-Planck Institute for Iron Research GmbH, Duesseldorf, Germany — 22, School of Materials, University of Science and Technology, Beijing, Beijing, China
Strong Goss texture {110}<001> in grain-oriented electrical steels forms by abnormal grain growth during high temperature recrystallization annealing. However, the cause of this abnormal growth has been disputed for more than 70 years. The various explanations include high fraction of high angle boundaries, high mobility of coincidence site lattice boundaries, size effects and so on. However, none of these explanations address the internal environment of Goss oriented grains. Here we use electron back scattering diffraction techniques and field emission microscopy to show that some Goss oriented grains in matrix have higher secondary particle densities than their neighbors during final annealing at 875 degree C before secondary recrystallization. Since regions with higher second phase particle density offer a high resistance to grain boundary migration, Goss oriented grains ought to grow more readily towards regions with lower secondary particle density. Therefore, we conclude that second phase particle densities must play a vital role in the growth of Goss oriented grains. This findings may shed light on optimizing Goss texture and improve magnetic properties of grain oriented electrical steels.