2002 Volume 88 Issue 3 Pages 155-162
The principal subjects discussed in this paper are the effects of cold rolling reduction on secondary recrystallization and magnetic properties of Fe-3%Si alloy. One-stage cold rolling process, which is known as a production method of high permeability grain-oriented silicon steel containing AlN precipitates, induced very unstable secondary recrystallization with too high cold reduction above 87%. Sharp deterioration of magnetic properties because of high reduction is related to the presence of fine grains, which mean poorly oriented grains deviating widely from the {110}<001>grains. This incomplete secondary recrystallization is supposed to be caused by the steps as follows: The higher cold rolling reduction causes the weaker {110}<001> orientation in primary recrystallized texture, and the secondary recrystallization temperature increases. The surface grains coarsen prior to secondary recrystallization. The larger surface grains, which are poorly oriented, consume the subsurface grains of the {110}<001> nuclei. Therefore the more fine grains were observed in the finally annealed structure with the higher reduction.
The two-stage cold rolling process was studied to clarify the effects of the first and second cold rolling reduction on secondary recrystallization. The second cold rolling affected magnetic properties rather than the first cold rolling in the two-stage cold rolling process.
