Journal of the Korean Society for Heat Treatment (열처리공학회지)

The Korean Society for Heat Treatment (한국열처리공학회)
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Effect of Ti Addition on the Microstructure and Grain Coarsening of SCR420H Steel

SCR420H강의 미세조직과 결정립 조대화에 미치는 Ti 첨가 영향

  • Jeonghu Choi (Division of Advanced Materials Engineering, Jeonbuk National University) ;
  • Sungjin Kim (Division of Advanced Materials Engineering, Jeonbuk National University) ;
  • Minhee Kim (Division of Advanced Materials Engineering, Jeonbuk National University) ;
  • Jaehyun Park (Division of Advanced Materials Engineering, Jeonbuk National University) ;
  • Jaehyeok Sin (Division of Advanced Materials Engineering, Jeonbuk National University) ;
  • Minhwan Ryu (Division of Advanced Materials Engineering, Jeonbuk National University) ;
  • Woochul Shin (Division of Advanced Materials Engineering, Jeonbuk National University) ;
  • Minwook Kim (R&D Center, SeAH Besteel) ;
  • Seok-Jae Lee (Division of Advanced Materials Engineering, Jeonbuk National University) ;
  • Jae-Gil Jung (Division of Advanced Materials Engineering, Jeonbuk National University)
  • 최정후 (전북대학교 신소재공학부) ;
  • 김성진 (전북대학교 신소재공학부) ;
  • 김민희 (전북대학교 신소재공학부) ;
  • 박재현 (전북대학교 신소재공학부) ;
  • 신재혁 (전북대학교 신소재공학부) ;
  • 류민환 (전북대학교 신소재공학부) ;
  • 신우철 (전북대학교 신소재공학부) ;
  • 김민욱 (세아베스틸 기술연구소) ;
  • 이석재 (전북대학교 신소재공학부) ;
  • 정재길 (전북대학교 신소재공학부)
  • Received : 2024.05.14
  • Accepted : 2024.06.13
  • Published : 2024.07.30
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Abstract

SCR420H steel is a low-carbon chromium alloy steel designed for carburizing heat treatment. Recently, research is being conducted on high-temperature carburization heat treatment to reduce costs and CO2 emissions by shortening the carburization time to meet the international carbon neutral policy. However, this high-temperature carburization heat treatment coarsens the steel grains and causes a decrease in mechanical properties. In this study, a large amount of Ti was added to increase the grain refinement effect in the high-temperature carburizing process. We investigated the microstructure and precipitates of SCR420H steel without Ti (Al steel) and with Ti (AlTi steel). Thermodynamic calculations showed that the AlN and (Ti,Nb)(C,N) precipitated in Al steel, while (Ti,Nb)(C,N) and Ti4C2S2 precipitated in AlTi steel. Addition of Ti increases the fraction of bainite after reheating process. Transmission electron microscopy analysis shows that small amounts of AlN and (Ti,Nb)(C,N) precipitates are formed in the Al steel. The addition of Ti increases the density of (Ti,Nb)(C,N) precipitates and induces the formation of Ti4C2S2 precipitates, increasing the grain coarsening temperature (GCT) under all heat treatment conditions. Higher reheating temperatures also resulted in higher GCT values due to increased precipitation.

Keywords

Acknowledgement

이 논문은 2024년도 정부(산업통상자원부)의 재원으로 한국산업기술진흥원의 지원을 받아 수행된 연구임(RS-2024-00410332, 2024년 산업혁신인재성장 지원사업).

References

  1. V. Boonmag, O. Wisesook, A. Phukaoluan, and G. Plupharch: Key Eng. Mater., 777 (2018), 294.
  2. V. Heuer, K. Loeser, and G. Schmitt: AGMA, 15 (2015), 9.
  3. Y. Yang, M. Wang, J. Chen, and H. Dong: J. Iron. Steel Res. Int., 20 (2013), 140.
  4. Y. H. Yang, M. Q. Chen, J. C. Chen, and H. Dong: J. Iron. Steel Res. Int., 20 (2013), 140.
  5. K. A. ALOGAB, D. K. MATLOCK, J. G. SPEER, and H. J. KLEEBE: ISIJ Int., 47 (2007), 307.
  6. G. Saito, N. Sakaguchi, M. Ohno, K. Matsuura, M. Takeuchi, T. Sano, K. Minoguchi, and T. Yamaoka: ISIJ Int., 60 (2020), 2549.
  7. M. Chapa, S. F. Medina, V. Lopez, and B. Fernandez: ISIJ Int., 42 (2002), 1288.
  8. G. Saito, N. Sakaguchi, K. Matsuura, T. Sano, and T. Yamaoka: ISIJ Int., 63 (2023), 727.
  9. C. M. Enloe, K. O. Findley, and J. G. Speer: Metall. Trans. A, 46 (2015), 5308.
  10. N. Z. Gutierrez, M. I. Luppo, and C. A. Danon: ISIJ Int., 47 (2007), 1178.
  11. K. A. Alogab, D. K. Matlock, J. G. Speer, and H. J. Kleebe: ISIJ Int., 47 (2007), 1034.
  12. R. Lagneborg, T. Siwecki, S. Zajac, and B. Hutchinson: Scand. J. Metall., 28 (1999), 186.
  13. S. Gong, L. Su, and F. Wang: Metall. Mater. Trans. A, 55 (2024) 910.
  14. K. Inoue, O. Ikuo, H. Ohtani, I. Kiyohito, and N. Taiji: ISIJ Int., 38 (1998), 991.
  15. G. Saito, N. Sakaguchi, M. Ohno, K. Matsuura, M. Takeuchi, T. Sano, K. Minoguchi, and T. Yamaoka: ISIJ Int., 60 (2020), 2549.
  16. H. Wada and R. D. Pehlke: Metall. Trans. B, 16 (1985), 815.
  17. B. Buchmayr: Steel Res. Int., 88 (2017), 10.
  18. Y. Shen and S. S. Hansen: Fatigue Fract. Eng. Mater. Struct., 20 (1997), 619.
  19. MatCalc 5.61, The materials calculator. https://www.matcalc.at/
  20. Y. Gang and K. Sorimachi: ISIJ Int., 35 (1995), 914.
  21. J. Y. Park, J. K. Park, and W. Y. Choo: ISIJ Int., 40 (2000), 1253.
  22. J. Zhao, J. H. Lee, Y. W. Jiang, Z. Jiang, and C. S. Lee: Mater. Sci. Eng., A, 559 (2013), 427.
  23. G. Krauss and S. W. Thompson: ISIJ Int., 35 (1995), 937.
  24. X. L. Han, D. Y. Min, X. L. Wang, B. Liao, and F. R. Xiao: Metals, 6 (2016), 75.
  25. B. Beidokhti, A. H. Koukabi, and A. Dolati: J. Mater. Process. Technol., 209 (2009), 4027.
  26. Y. Shan, X. Luo, X. Hu, and S. Liu: J. Mater. Sci. Technol., 27 (2010), 352.
  27. M. Kapoor, R. O'Malley, and G. B. Thompson: Metall. Mater. Trans. A, 47 (2016), 1984.
  28. V. Y. Novikov: Scr. Mater., 37 (1997), 463.
  29. J. M. Kim, S. Y. Hong, J. H. Jang, and K. J. Lee: Mater. Sci. Forum., 879 (2017), 921.