Carbide-free-bainite in low carbon construction steels

A.Y. Kaletin ORCID logo , J.V. Kaletina, M.A. Ryzhkov show affiliations and emails
Received 17 February 2020; Accepted 16 April 2020;
This paper is written in Russian
Citation: A.Y. Kaletin, J.V. Kaletina, M.A. Ryzhkov. Carbide-free-bainite in low carbon construction steels. Lett. Mater., 2020, 10(3) 249-253
BibTex   https://doi.org/10.22226/2410-3535-2020-3-249-253

Abstract

A feature of the bainitic structure formed upon slow continuous cooling of chromium-nickel-molybdenum steels containing 0.1-0.15% C is the complete absence of precipitates of the carbide phase. It has been shown that carbide-free bainite in such steels is a two-phase ferrite-austenitic structure and, at almost the same level of strength, has a higher level of toughness than steel with bainite containing carbide precipitates.In this work the structure and mechanical properties of chromium-nickel-molybdenum steels with a carbon content of 0.1 to 0.2% after austenitization and slow continuous cooling in the bainitic region at a rate of about 5°C/min were investigated. It was shown that at a carbon content of about 0.10...0.15% after such heat treatment, a carbide-free bainite structure is formed in steel, which is a two-phase mixture of bainitic ferrite and residual austenite supersaturated with carbon. Using transmission electron microscopy, the features of the formed bainitic ferrite and the distribution of retained austenite, the amount of which ranged from 10 to 14%, were studied. Using X-ray phase analysis, the carbon content in the retained austenite was determined, which turned out to be equal to 0.8 ... 0.9% C. An increase in carbon content up to 0.2% in such steels leads to the precipitation of carbide particles during bainitic transformation with continuous cooling. After additional doping with silicon in an amount of about 1% in the steel of such an alloying system with 0.2% C, the formation of carbides is almost completely suppressed and carbide-free bainite is formed, while the amount and degree of enrichment of retained austenite in carbon slightly increases. Comparison of the mechanical properties of the investigated low-carbon steels showed that at approximately the same level of strength, steels with carbide-free bainite have a higher level of toughness compared to steel containing carbide precipitates. Retained austenite in carbide-free bainite is substantially carbon enriched and contains a significant portion of the total carbon content in steel.

References (19)

1. C. Hofer, H. Leitner, F. Winkenhofer, H. Clemens, S. Primig. Mater. Char. 102, 85 (2015). Crossref
2. H. K. D. H. Bhadeshia. Bainite in Steels: Theory and Practice, 3d ed. London, CRC Press (2015) 616 p.
3. F. G. Caballero, H. K. D. H. Bhadeshia. Current Opinion in Solid State and Materials Science DK. 8, 251 (2004). Crossref
4. C. Garcia-Mateo, F. G. Caballero, H. K. D. H. Bhadeshia. Materials Science Forum. 500, 495 (2005).
5. M. Soliman, H. Mostafa, A. S. El-Sabbah, H. Palkovski. Mater. Sci. Eng. A. 527, 7706 (2010). Crossref
6. X. Y. Long, J. Kang, B. Ly, F. C. Zhang. Materials and Design. 64, 237 (2014). Crossref
7. Z. Bojarski, T. Bold. Acta Met. 22 (10), 1223 (1974). Crossref
8. J. C. Hell, M. Dehmas, S. Allain, J. M. Prado. ISIJ international. 51, 1724 (2011). Crossref
9. Yu. M. Kaletin, A. G. Ryzhkov, A. Yu. Kaletin. Izvestiy Vuzov. Chernaya Metallurgya. 6, 96 (1989). (in Russian) [Ю. М. Калетин, А. Г. Рыжков, А. Ю. Калетин. Известия Вузов. Черная металлургия. 6, 96 (1989).].
10. A. V. Makarov, L. G. Korshunov, I. L. Solodova. Friction and wear. 21, 501 (2000). (in Russian) [А. В. Макаров, Л. Г. Коршунов, И. Л. Солодова. Трение и износ. 21, 501 (2000).].
11. A. V. Makarov, V. M. Schastlivtsev, T. I. Tabatchikova. Deformation and fracture of materials. 6, 1 (2010). (in Russian) [А. В. Макаров, В. М. Счастливцев, Т. И. Табатчикова. Деформация и разрушение материалов. 6, 1 (2010).].
12. M. N. Georgiev, A. Yu. Kaletin, Yu. N. Simonov, V. M. Schastlivtsev. Phys. Metals Metallogr. 1, 113 (1990). (in Russian) [М. Н. Георгиев, А. Ю. Калетин, Ю. Н. Симонов, В. М. Счастливцев. ФММ. 1, 113 (1990).].
13. V. M. Schastlivtsev, Yu. V. Kaletina, E. A. Fokina, A. Yu. Kaletin. Phys. Metals Metallogr. 115, 962 (2014). (in Russian) [В. М. Счастливцев, Ю. В. Калетина, Е. А. Фокина, А. Ю. Калетин. ФММ. 115, 962 (2014).]. Crossref
14. V. M. Schastlivtsev, Yu. V. Kaletina, E. A. Fokina, A. Yu. Kaletin. Phys. Metals Metallogr. 115, 1052 (2014). (in Russian) [В. М. Счастливцев, Ю. В. Калетина, Е. А. Фокина, А. Ю. Калетин. ФММ. 115, 1052 (2014).]. Crossref
15. A. Yu. Kaletin, Yu. V. Kaletina. Phys. Solid State. 57, 56 (2015). (in Russian) [А. Ю. Калетин, Ю. В. Калетина. ФТТ. 57, 56 (2015).].
16. A. Yu. Kaletin, A. G. Ryzhkov, Yu. V. Kaletina. Phys. Metals Metallogr. 116, 114 (2015). (in Russian) [А. Ю. Калетин, А. Г. Рыжков, Ю. В. Калетина. ФММ. 116, 114 (2015).]. Crossref
17. Yu. N. Simonov, M. Yu. Simonov, D. O. Panov, V. P. Vylezhnev, A. Yu. Kaletin. Metal Science and Heat Treat. Metals. 2, 4 (2016). (in Russian) [Ю. Н. Симонов, М. Ю. Симонов, Д. О. Панов, В. П. Вылежнев, А. Ю. Калетин. МиТОМ. 2, 4 (2016).].
18. D. O. Panov, Yu. N. Simonov, P. A. Leontiev, A. Yu. Kaletin. Metal Science and Heat Treat. Metals. 2, 13 (2016). (in Russian) [Д. О. Панов, Ю. Н. Симонов, П. А. Леонтьев, А. Ю. Калетин. МиТОМ. 2, 13 (2016).].
19. A. Yu. Kaletin, Yu. V. Kaletina. Phys. Metals Metallogr. 119, 946 (2018). (in Russian) [А. Ю. Калетин, Ю. В. Калетина. ФММ. 119, 946 (2015).]. Crossref

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Funding

1. Ministry of Education and Science of the Russian Federation - theme “Pressure” No. АААА-А18‑118020190104‑3 and theme “Structure” No. АААА-А18‑118020190116‑6 with partial support from the Comprehensive Program of the Ural Branch of the RAS project No. 18‑20‑2‑24 and RFBR project No. 20‑03‑00056