Thixomet JSC (St. Petersburg, Russia):

A. A. Kazakov, Dr. Eng., Prof., Head of the Metallurgical Expertise Laboratory, e-mail: kazakov@thixomet.ru
D. V. Kiselev, Technical Director

National Research Centre "Kurchatov Institute" — Central Research Institute of Structural Materials "Prometey" (St. Petersburg, Russia):
O. V. Sych, Cand. Eng., Head of the Sector
E. I. Khlusova, Dr. Eng., Prof., Deputy Head of Scientific and Production Centre No. 3 (NPK-3), Head of the Laboratory

A technique for microstructure anisotropy assessing by the thickness of the plate steel based on the textural analysis of the image has been developed. The technique covers the assessing of anisotropy criteria at two dimensional levels: in the near and far surroundings, which characterize the elongation along the rolling direction of fine and coarse structural elements, respectively. The results of the technique application for the microstructural heterogeneity studying of ferrite-bainite steel by the thickness of 25 mm plate steel are presented. It is shown that the proposed anisotropy criteria in combination with the total volume fraction of coarse packet-block regions of lath bainite and regions of bainite without an internal developed subgrain structure adequately describe the heterogeneity of the microstructure across the thickness of plate steel and can be used for a detailed interpretation of the two-stage thermomechanical processing technology with accelerated cooling, taking into account metallurgical heredity of the slab.
E. I. Kazakova, M. V. Salynova, O. V. Pakhomova, L. S. Chigintsev, A. I. Zhitenev participated in this work.

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