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METAL SCIENCE AND HEAT TREATMENT
ArticleName Interpretation of distribution of microstructural heterogeneity across the plate steel thickness
DOI 10.17580/chm.2021.04.06
ArticleAuthor A. A. Kazakov, D. V. Kiselev, O. V. Pakhomova, O. V. Sych
ArticleAuthorData

Peter the Great St. Petersburg State Polytechnic University (St. Petersburg, Russia):

A. A. Kazakov, Dr. Eng., Prof., Head of the Metallurgical Expertise Laboratory, e-mail: kazakov@thixomet.ru
D. V. Kiselev, 1st Category Engineer
O. V. Pakhomova, Chief Engineer

 

National Research Centre “Kurchatov Institute” - Central Research Institute of Structural Materials “Prometey” (St. Petersburg, Russia):
O. V. Sych, Cand. Eng., Head of the Sector

Abstract

The relationships of the anisotropy behavior and other characteristics of structural heterogeneity over the thickness of the plate have been established and their microstructural interpretation has been presented using the example of low-alloy plate steel. The features of structure formation from the surface to the center of 100 mm thick plate metal have been considered with a detailed description of the structure evolution and the processes that caused these changes. It was found that a fine quasi-homogeneous structure consisting of lath bainite and granular bainite provides anisotropy Ka100 <1 and occupies a narrow layer from 5 to 17 mm from the plate surface. In the near-surface layer, due to the abnormal structure consisting of large austenite grains elongated along the rolling direction and decorated with allotriomorphic ferrite, the anisotropy is Ka100 > 1. In a quarter of the plate thickness, due to weak fragmentation of the structure, the anisotropy is Ka100 > 1. In the center of the plate, quasi-polygonal and polygonal ferrite absorbs all extended boundaries of the former austenite grains; therefore, Ka100 becomes again less than unity.

keywords Cold-resistant low alloy plate steel, structural heterogeneity over thickness, image analysis, anisotropy, structure interpretation
References

1. Araki T., Kozasu I., Tankechi Н., Shibata K., Enomoto M., Tamehiro H. et al. Atlas for bainitic microstructures. ISIJ International. 1992. Vol. 1. pp. 1–20.
2. Bhadeshia H. K. D. H. Bainite in steels: transformations, microstructure and properties. London : IOM Communications, 2001.
3. Wilson E. A. The γ→α transformation in low carbon irons. ISIJ International. 1994. Vol. 34. Iss. 8. pp. 615–630.
4. Edmonds D. V. New aspects of microstructures in modern low carbon high strength steels. Tokyo: ISIJ International, 1994. 99 p.
5. Krauss G., Thompson S. W. Ferritic microstructures in continuously cooled low- and ultralow-carbon steels. ISIJ International. 1995. Vol. 35. Iss. 8. pp. 937–945.
6. Kazakov А. А., Kiselev D. V., Sych О. V., Khlusova Е. I. The technique for assessment of microstructural heterogeneity across thickness of plate made of cold-resistant low-alloy steel for Arctic applications. Chernye Metally. 2020. No. 9. pp. 11–19.
7. Kazakov А. А., Kazakova E. I., Kiselev D. V., Kurochkina O. V. Investigation method of structure of tube steels. Patent RF No. 2449055. Applied: 18.10.2010. Published: 27.04.2012. Bulletin No. 12.
8. Kazakov А. А., Kiselev D. V., Sych О. V., Khlusova Е. I. Quantitative assessment of structural inhomogeneity in cold-resistant low-alloy steel sheets for interpretation of technological features of their manufacturing. Chernye Metally. 2020. No. 11. pp. 4–14.
9. Cizek P., Wynne B. P., Davies C. H. J.et al. Effect of composition and austenite deformation on the transformation characteristics of low-carbon and ultralow-carbon microalloyed steels. Metallurgical and Materials Transactions A. 2002 Vol. 33. No. 5. pp. 1331–1349.
10. Lan L., Chang Z., Kong X. et al. Phase transformation, microstructure, and mechanical properties of X100 pipeline steels based on TMCP and HTP concepts. Journal of Materials Science. 2017. Vol. 52. pp. 1661–1678.
11. Hui G., Yin B., Yun D., Shan W. Y., Xin L. H. Influence of allotriomorphic ferrite under different growth modes on the variant selection of bainite in a low carbon steel. Advanced Materials Research. 2011. Vol. 399-401. pp. 200–205.
12. Zajac S., Schwinn V., Tacke K. H. Characterisation and quantification of complex bainitic microstructures in high and ultra-high strength linepipe steels. Materials Science Forum. 2005. Vol. 500-501. pp. 387–394.
13. Golubeva М. V., Sych О. V., Khlusova Е. I., Motovilina G. D. Study of mechanical properties and failure behavior of new economically alloyed cold-resistant steel with a guaranteed yield strength of 690 MPa. Aviatsionnye Materialy i Technologii. 2017. Vol. 49. No. 4. pp. 19–24.
14. Ben Hag Slama M., Gey N., Germain L., Zhu K., Allain S. Key parameters to promote granularization of lath-like bainite / martensite in FeNiC alloys during isothermal holding. Materials. 2018. Vol. 11. No. 10. P. 1808.
15. Ghasemi Banadkouki S. S., Dunne D. P. Formation of ferritic products during continuous cooling of a Cu-bearing HSLA steel. ISIJ International. 2006. Vol. 46. Iss. 5. pp. 759–768.
16. Pak J., Dong W. S., Bhadeshia H. K. D. H. Promoting the coalescence of bainite platelets. Scripta Materialia. 2012. Vol. 66. pp. 951–953.
17. Rios P. R., Siciliano Jr F., Sandim H. R. Z., Plaut R. L., Padilha A. F. Nucleation and growth during recrystallization. Materials Research. 2005. Vol. 8. No. 3. pp. 225–238.

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