2013 Volume 54 Issue 1 Pages 14-21
A grain-oriented electrical steel has a significantly low iron loss by selective growth of grains with {110}< 001> orientation called as Goss orientation. The selective growth of Goss grains is generally attained by making use of a phenomenon termed ‘secondary recrystallization’. We have already investigated primary recrystallized grains encroached easily by Goss grain and discussed influence of primary-recrystallization texture on the selective growth of Goss grains roughly.
This paper investigates normal growth behavior of primary recrystallized grains in the middle of secondary-recrystallization annealing and discusses influence of primary-recrystallization texture on the selective growth of Goss grains in detail. In this study, several grain-oriented electrical steel samples were prepared by controlling the heating pattern in secondary-recrystallization annealing. The primary-recrystallization texture and primary recrystallized grain size were measured in samples before secondary-recrystallization annealing and in the middle of secondary-recrystallization annealing.
The results are as follows. (1) In secondary-recrystallization annealing, the normal grain growth of primary recrystallized grains having misorientation angle between 25–40 degree to Goss orientation was high. (2) It was considered that the normal grain growth in the middle of secondary-recrystallization annealing had a large influence on selective growth of Goss grain. (3) The change of primary-recrystallization texture in the middle of secondary between heating patterns was caused by the change of the normal grain growth.
Next, we predicted crystal orientation after the secondary recrystallization by the analysis of primary-recrystallization texture in the middle of secondary-recrystallization annealing. In the prediction, the frequency and the mobility dependence of misorientation angle are taken into account.
The expected result showed good agreement with the experimental result. This result was the same as the reported result before. Additionally, it was considered that the nucleation frequency of Goss grain in the primary-recrystallization texture had influence on this expectation.
