DOI: https://doi.org/10.15802/stp2020/208234

FORMATION OF CARBON STEEL STRUCTURE DURING HOT PLASTIC DEFORMATION

I. O. Vakulenko, D. M. Bolotova, S. V. Proidak, H. Askerov, H. Cug, H. O. Tchaikovska

Abstract


Purpose. The main purpose of the work is to determine the peculiarities of the development of recrystallization processes of carbon steel austenite depending on the degree of hot plastic deformation and to develop proposals for improving the structural state of the metal of the railway solid-rolled wheel. Methodology. Two carbon steels of a railway wheel with a minimum and maximum carbon content of 0.55 and 0.65 % and other chemical elements within the grade composition of the steel 60 were used as research material. Samples in the form of cylinders with a diameter of 20 mm and a height of 40 mm were heated in a muffle furnace, exposed for a certain time to equalize the temperature across the cross section of the sample. After that, the samples were subjected to hot compression on Instron type test machine. The temperature interval of hot compression of the samples was 950–1100 ºС, with deformation degrees in height in the range of 10–40%. The strain rate was 10-3–10-2sec-1. A standard etching was used to detect the boundaries of the austenite grains. Structural studies were performed using Epikvant type light microscope at magnifications sufficient to determine the structure of austenite grains. The grain size of austenite was determined by the methods of quantitative metallography. Findings. In the case of hot compression of the railway wheel blank, increasing the concentration of carbon atoms only within the grade composition of the steel is sufficient to increase the average austenite grain size, which confirms the proposals to limit the carbon content in the metal of railway wheels. The formation of a certain degree of austenite structural heterogeneity at the cross section of the rim or hub of the railway wheel is due to a change in the development mechanism of recrystallization processes depending on the deformation value. Under conditions of the same degree of hot plastic deformation, the replacement of one-time compression by fractional one is accompanied by a violation of the conditions of formation of the recrystallization nucleus. As a result of the specified replacement of the scheme of hot plastic deformation we obtain reduction in the austenite grain size. Originality. Based on a study of the development of collective recrystallization processes during the hot compression of carbon steel of the railway wheel, it was determined that the increase in carbon content contributes to the austenite grain increase. After hot compression of the wheel blank, the structural inhomogeneity of austenite that occurs is determined by a change in the mechanism of recrystallization processes development. During deformations above the critical degree, the recrystallization nuclei are formed and successively grow, which leads to the structure refinement. In the case of deformations below the critical value, the growth of austenite grains occurs according to the coalescence mechanism, according to which fragments of boundaries with large disorientation angles consistently disappear. Practical value. For austenite grain refining in massive elements of solid-rolled railway wheel we offer to replace one-time hot compression by fractional one.


Keywords


austenite; deformation; temperature; grain size; carbon steel; railway wheel

References


Vakulenko, I. A., & Bolshakov, V. I. (2008). Morfologiya struktury i deformatsionnoe uprochnenie stali. Dnepropetrovsk: Makovetskiy Y. V. (in Russian)

Vakulenko, I., Perkov, O., & Stradomski, Z. (2015). Influence of Temperature and Value of Hot Deforma Tion on Size of Gra in a Ustenite at Making of Railway Wheels. Copyright by Wydawnictwo Wydzialu Inzynierii Produkeji I Technologii Materialow Politechniki Czestochowskiej. New technolоgies and achievements in metallurgy, material engineering and production engineering:Collective monograph ХVІ International Scientific Conference. Czestochowa, 48, 365-368. (in Russian)

Uzlov, I. G., Perkov, O. N., & Vakulenko, I. A. (2002). Vliyanie skhemy goryachey deformatsii zagotovki na svoystva metalla oboda tselnokatanykh zheleznodorozhnykh koles. Fundamentalnye i prikladnye problemy chernoy metallurgii, 5, 196-199. (in Russian)

Shifrin, M. Yu., Andreev, Yu. V., & Likhoshvayj, V. A. (1970). Vliyanie deformatsii zagotovki na pressakh i v kolesoprokatnom stane na mekhanicheskie svoystva diska i oboda tselnokatanykh koles. Kuznechno-shtampovochnoe proizvodstvo, 8, 7-11. (in Russian)

Banerjee, A., Hossain, R., Pahlevani, F., Zhu Q., Sahajwalla V., & Prusty G. (2019). Strain-rate-dependent deformation behaviour of high-carbon steel in compression: mechanical and structural characterization. Journal of Materials Science, 54(8), 6594-6607. DOI: https://doi.org/10.1007/s10853-018-03301-x (in English)

Hossain, R., Pahlevani, F., Quadir ,M. Z., & Sahajwalla, V. (2016). Stability of retained austenite in high carbon steel under compressive stress: an investigation from macro to nano scale. Scientific Reports, 6, 1-11. DOI: https://doi.org/10.1038/srep34958 (in English)

Hubbard, D. (2016). Plastic Deformation: Processes, Properties and Applications. USA: Nova Science Publishers. (in English)

Ławrynowicz, Z. (2015). Plastic deformation and softening of the surface layer of railway wheel. Advances in Materials Science, 15(4), 6-13. DOI: https://doi.org/10.1515/adms-2015-0018 (in English)

Mirzadeh, H. (2015). Constitutive modeling and prediction of hot deformation flow stress under dynamic recrystallization conditions. Mechanics of Materials, 85, 66-79.DOI: https://doi.org/10.1016/j.mechmat.2015.02.014 (in English)

Qiu, C., Cookson, J., & Mutton, P. (2017). The role of microstructure and its stability in performance of wheels in heavy haul service. Journal of Modern Transportation, 25(4), 261-267. DOI: https://doi.org/10.1007/s40534-017-0143-9 (in English)

Ren, X., Qi, J., Gao, J., Wen, L., Jiang, B., Chen, G., & Zhao, H. (2016). Effects of Heating Rate on Microstructure and Fracture Toughness of Railway Wheel Steel. Metallurgical and Materials Transactions A, 47(2), 739-747. DOI: https://doi.org/10.1007/s11661-015-3264-y (in English)

Shen, X., Yan, J., Zhang, L., Gao, L., & Zhang, J. (2013). Austenite grain size evolution in railway wheel during multi-stage forging processes. Journal of Iron and Steel Research Internation, 20(3), 57-65. DOI: https://doi.org/10.1016/s1006-706x(13)60070-9 (in English)

Zhao, H., Qi, J., Su, R., Zhang, H., Chen, H., Bai, L., & Wang, C. (2020). Hot deformation behaviour of 40CrNi steel and evaluation of different processing map construction methods. Journal Materials Research and Technology, 9(3), 2856-2869. DOI: https://doi.org/10.1016/j.jmrt.2020.01.020 (in English)

Wang, J., Xiao, H., Xie, H. B., & Xu, X. M. (2011). Simulation of Recrystallization Behavior and Austenite Grain Size Evolution during Hot Deformation of Low Carbon Steel Using the Flow Stress. Advanced Materials Research, 337, 178-183. DOI: https://doi.org/10.4028/www.scientific.net/AMR.337.178 (in English)


GOST Style Citations


  1. Вакуленко И. А., Большаков В. И. Морфология структуры и деформационное упрочнение стали. Днипро : Маковецкий, 2008. 196 с.
  2. Вакуленко И., Перков О., Страдомски З. Влияние температуры величины горячей деформации на размер зерна аустенита при изготовлении железнодорожных колес. Copyright by Wydawnictwo Wydzialu Inzynierii Produkeji I Technologii Materialow Politechniki Czestochowskiej. New technolоgies and achievements in metallurgy, material engineering and production engineering : Collective monograph ХVІ International Scientific Conference. Czestochowa, 2015. № 48. С. 365–368.
  3. Узлов И. Г., Перков О. Н., Вакуленко И. А. Влияние схемы горячей деформации заготовки на свойства металла обода цельнокатаных железнодорожных колес. Фундаментальные и прикладные проблемы черной металлургии. 2002. Вып. 5. С. 196–199.
  4. Шифрин М. Ю., Андреев Ю. В., Лихошвай В. А. Влияние деформации заготовки на прессах и в колесопрокатном стане на механические свойства диска и обода цельнокатаных колес. Кузнечно-штамповочное производство. 1970. № 8. С. 7–11.
  5. Banerjee A., Hossain R., Pahlevani F., Zhu Q., Sahajwalla V. Prusty G. Strain-rate-dependent deformation behaviour of high-carbon steel in compression : mechanical and structural characterization. Journal of Materials Science. 2019. Vol. 54. Iss. 8. P. 6594–6607. DOI: https://doi.org/10.1007/s10853-018-03301-x
  6. Hossain R., Pahlevani F., Quadir M. Z. Sahajwalla V. Stability of retained austenite in high carbon steel under compressive stress : an investigation from macro to nano scale. Scientific Reports. 2016. Vol. 6. P. 1–11. DOI: https://doi.org/10.1038/srep34958
  7. Hubbard D. Plastic Deformation : Processes, Properties and Applications. USA : Nova Science Publishers, 2016. 198 р.
  8. Ławrynowicz Z. Plastic deformation and softening of the surface layer of railway wheel. Advances in Materials Science. 2015. Vol.15. Iss. 4. P. 6–13. DOI: https://doi.org/10.1515/ adms-2015-0018
  9. Mirzadeh H. Constitutive modeling and prediction of hot deformation flow stress under dynamic recrystallization conditions. Mechanics of Materials. 2015. Vol. 85. P. 66–79.
    DOI: https://doi.org/10.1016/j.mechmat.2015.02.014
  10. Qiu C., Cookson J., Mutton P. The role of microstructure and its stability in performance of wheels in heavy haul service. Journal of Modern Transportation. 2017. Vol. 25. Iss. 4. P. 261–267.
    DOI: https://doi.org/10.1007/s40534-017-0143-9
  11. Ren X., Qi J., Gao J., Wen L., Jiang B., Chen G., Zhao H. Effects of Heating Rate on Microstructure and Fracture Toughness of Railway Wheel Steel. Metallurgical and Materials Transactions A. 2016. Vol. 47. Iss. 2. P. 739–747. DOI: https://doi.org/10.1007/s11661-015-3264-y
  12. Shen X., Yan J., Zhang L., Gao L., Zhang J. Austenite grain size evolution in railway wheel during multi-stage forging processes. Journal of Iron and Steel Research Internation. 2013. Vol. 20. Iss. 3. P. 57–65. DOI: https://doi.org/10.1016/s1006-706x(13)60070-9
  13. Zhao H., Qi J., Su R., Zhang H., Chen H., Bai L., & Wang C. Hot deformation behaviour of 40CrNi steel and evaluation of different processing map construction methods. Journal Materials Research and Technology. 2020. Vol. 9. Iss. 3. P. 2856–2869. DOI: https://doi.org/10.1016/j.jmrt.2020.01.020
  14. Wang J., Xiao H., Xie H. B., Xu X. M. Simulation of Recrystallization Behavior and Austenite Grain Size Evolution during Hot Deformation of Low Carbon Steel Using the Flow Stress. Advanced Materials Research. 2011. Vol. 337. P. 178–183. DOI: https://doi.org/10.4028/www.scientific.net/AMR.337.178




Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.

 

ISSN 2307–3489 (Print)
ІSSN 2307–6666 (Online)