Korean Journal of Materials Research (한국재료학회지)

Materials Research Society of Korea (한국재료학회)
권호 표지
DOI QR코드

DOI QR Code

Effect of Vanadium and Boron on Microstructure and Low Temperature Impact Toughness of Bainitic Steels

베이나이트강의 미세조직과 저온 충격 인성에 미치는 바나듐과 보론의 영향

  • Huang, Yuanjiu (School of Materials Science and Engineering, University of Ulsan) ;
  • Lee, Hun (School of Materials Science and Engineering, University of Ulsan) ;
  • Cho, Sung Kyu (Technical Research Center, Hyundai Steel Company) ;
  • Seo, Jun Seok (Technical Research Center, Hyundai Steel Company) ;
  • Kwon, Yongjai (School of Materials Science and Engineering, University of Ulsan) ;
  • Lee, Jung Gu (School of Materials Science and Engineering, University of Ulsan) ;
  • Shin, Sang Yong (School of Materials Science and Engineering, University of Ulsan)
  • 황원구 (울산대학교 첨단소재공학과) ;
  • 이훈 (울산대학교 첨단소재공학과) ;
  • 조성규 (현대제철 기술연구소) ;
  • 서준석 (현대제철 기술연구소) ;
  • 권용재 (울산대학교 첨단소재공학과) ;
  • 이정구 (울산대학교 첨단소재공학과) ;
  • 신상용 (울산대학교 첨단소재공학과)
  • Received : 2021.01.29
  • Accepted : 2021.02.08
  • Published : 2021.03.27
Download PDF
⟨ Previous Next ⟩

Abstract

In this study, three kinds of bainitic steels are fabricated by controlling the contents of vanadium and boron. High vanadium steel has a lot of carbides and nitrides, and so, during the cooling process, acicular ferrite is well formed. Carbides and nitrides develop fine grains by inhibiting grain growth. As a result, the low temperature Charpy absorbed energy of high vanadium steel is higher than that of low vanadium steel. In boron added steel, boron segregates at the prior austenite grain boundary, so that acicular ferrite formation occurs well during the cooling process. However, the granular bainite packet size of the boron added steel is larger than that of high vanadium steel because boron cannot effectively suppress grain growth. Therefore, the low temperature Charpy absorbed energy of the boron added steel is lower than that of the low vanadium steel. HAZ (heat affected zone) microstructure formation affects not only vanadium and boron but also the prior austenite grain size. In the HAZ specimen having large prior austenite grain size, acicular ferrite is formed inside the austenite, and granular bainite, bainitic ferrite, and martensite are also formed in a complex, resulting in a mixed acicular ferrite region with a high volume fraction. On the other hand, in the HAZ specimen having small prior austenite grain size, the volume fraction of the mixed acicular ferrite region is low because granular bainite and bainitic ferrite are coarse due to the large number of prior austenite grain boundaries.

Keywords

References

  1. D. S. Liu, Q. L. Li and T. Emi, Metall. Mater. Trans. A, 42, 1349 (2011). https://doi.org/10.1007/s11661-010-0458-1
  2. Y. L. Zhou, T. Jia, X. J. Zhang, Z. Y. Liu and R. D. K. Misra, Mater. Sci. Eng., A, 626, 352 (2015). https://doi.org/10.1016/j.msea.2014.12.074
  3. B. L. Bramfitt and J. G. Speer, Metall. Trans. A, 21, 817 (1990). https://doi.org/10.1007/BF02656565
  4. M. Chapa, S. F. Medina, V. Lopez and B. Fernandez, ISIJ Int., 42, 1 (2002). https://doi.org/10.2355/isijinternational.42.1
  5. A. D. Schino and C. Guarnaschelli, Mater. Lett., 63, 1968 (2009). https://doi.org/10.1016/j.matlet.2009.06.032
  6. A. D. Schino, L. Alleva and M. Guagnelli, Mater. Sci. Forum, 715-716, 860 (2012). https://doi.org/10.4028/www.scientific.net/msf.715-716.860
  7. C. Yu, T. C. Yang, C. Y. Huang and R. K. Shiue, Metall. Mater. Trans. A, 47A, 4777 (2016).
  8. S. K. Dhua, D. Mukerjee and D. S. Sarma, Metall. Mater. Trans. A, 32A, 2259 (2001).
  9. B. Hwang, C. G. Lee and S. J. Kim, Metall. Mater. Trans. A, 42A, 717 (2011).
  10. T. C. Yang, C. Y. Huang, T. C. Cheng, C. Yu and R. K. Shiue, Adv. Mater. Res., 936, 1312 (2014). https://doi.org/10.4028/www.scientific.net/AMR.936.1312
  11. G. Heigl, H. Lengauer and P. Hodnik, Steel Res. Int., 79, 931 (2008). https://doi.org/10.1002/srin.200806223
  12. B. C. Kim, S. Lee, N. J. Kim and D. Y. Lee, Metall. Mater. Trans. A, 22A, 139 (1991).
  13. N. Yurioka, Weld. World, 35, 375 (1995).
  14. R. E. Dolby, Weld. Res. Int., 7, 298 (1977).
  15. Y. Zhang, X. Li and H. Ma, Metall. Mater. Trans. B, 47, 2148 (2016). https://doi.org/10.1007/s11663-015-0534-4
  16. X. L. Wang, Y. T. Tsai, J. R. Yang, Z. Q. Wang, X. C. Li, C. J. Shang and R. D. K. Misra, Weld. World, 61, 1155 (2017). https://doi.org/10.1007/s40194-017-0498-x
  17. Y. Q. Zhang, H. Q. Zhang, W. M. Liu and H. Hou, Mater. Sci. Eng., A, 499, 182 (2009). https://doi.org/10.1016/j.msea.2007.10.118
  18. J. Hu, L.-X. Du, J.-J. Wang and C.-R. Gao, Mater. Sci. Eng., A, 577, 161 (2013). https://doi.org/10.1016/j.msea.2013.04.044
  19. H. K. Sung, S. Y. Shin, B. Hwang, C. G. Lee and S. Lee, Metall. Mater. Trans. A, 43A, 3703 (2012).
  20. S. Kim, Y. Kang and C. Lee, Mater. Charact., 116, 65 (2016). https://doi.org/10.1016/j.matchar.2016.04.004
  21. T. Araki, Atlas for Bainitic Microstructures, p. 1, ISIJ, Tokyo, Japan (1992).
  22. G. Krauss and S. W. Thompson, ISIJ Int., 35, 937 (1995). https://doi.org/10.2355/isijinternational.35.937
  23. H. K. D. H. Bhadeshia, Mater. Sci. Eng., A, A378, 34 (2004). https://doi.org/10.1016/j.msea.2003.10.328
  24. D. Deng and S. Kiyoshima, Comput. Mater. Sci., 62, 23 (2012). https://doi.org/10.1016/j.commatsci.2012.04.037
  25. H. Qiu, M.Enoki, Y. Kawaguchi and T. Kishi, ISIJ Int., 40, S34 (2000). https://doi.org/10.2355/isijinternational.40.Suppl_S34
  26. M. M. Giangregorio, M. Losurdo, G. V. Bianco, E. Dilonardo, P. Capezzuto and G. Bruno, Mater. Sci. Eng., B, 179, 559 (2013).
  27. B. Hutchinson, J. Komenda, G. S. Rohrer and H. Beladi, Acta Mater., 97, 380 (2015). https://doi.org/10.1016/j.actamat.2015.05.055