Inhomogeneous Distributions of Sub-Grains and Precipitates in Strip-Cast 3wt% Si Steel Sheet

Abstract:

A Fe-3wt% Si strip was produced using a vertical type twin-roll casting process. Sub-grains with an inhomogeneous distribution through the thickness direction were firstly observed in the as-cast strip. It was found that the surface layer was characterized by columnar grains containing lineage sub-grains, the subsurface layer was dominated by numerous polygonal sub-grains inside columnar grains or fine equiaxed grains, and the center layer was composed of coarse equiaxed grains without sub-grains. In addition, the sub-grain boundaries provided additional nucleation sites for precipitates and the nanoscale MnS particles were successfully obtained. Moreover, the average size of MnS precipitates in the surface layer was smaller than that in the subsurface layer. The inhomogeneous distributions of sub-grains and precipitates can be attributed to the large temperature gradient through the thickness direction during the strip casting process.

• Periodical: Materials Science Forum (Volume 850)
• Pages: 549-553
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.850.549
• Online since: March 2016
• Authors: Yang Wang, Yun Bo Xu, Y.X. Zhang, Feng Fang, Xiang Lu, Guo Dong Wang
• Keywords: Grain Oriented Electrical Steel, Precipitation, Strip Casting, Substructure

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