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Effects of Start and Finish Cooling Temperatures on the Yield Strength and Uniform Elongation of Strain-Based API X100 Pipeline Steels

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Abstract

Three types of strain-based API X100 pipeline steels composed of polygonal ferrite (PF), acicular ferrite (AF), granular bainite (GB), bainitic ferrite (BF), and martensite–austenite (MA) were fabricated by varying the start cooling temperature (SCT) and finish cooling temperature (FCT). The effect of the microstructure on the yield strength and uniform elongation before and after strain aging was investigated. In the H-H steel fabricated at a high SCT and low FCT, the reduction in uniform elongation after prestraining was small, but the uniform elongation after heat treatment increased because of the presence of many mobile dislocations around AF and GB, which are present in a relatively high fraction. Because the H-L steel fabricated at high SCT and low FCT has a considerable amount of BF as a result of the significant degree of supercooling, carbon atoms were readily trapped at dislocations inside the BF during heat treatment, which reduced the resistance to strain aging. On the other hand, the L-L steel had a large amount of soft PF transformed in the two-phase (austenite + ferrite) region and high fractions of AF and MA because it was fabricated at low SCT and low FCT. As a result, the uniform elongation of the L-L steel was slightly increased after heat treatment because mobile dislocations were readily generated around the PF and MA boundaries under deformation.

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References

  1. I. Tamura, H. Sekine, T. Tanaka, and C. Ouchi: Thermomechanical Processing of High-Strength Low-Alloy Steels, Butterworth–Heinemann, Oxford, England, 1988, pp. 80–100.

    Book  Google Scholar 

  2. US Patent Pub., 2007, No. 20070193666.

  3. Y. Shinohara, T. Hara, E. Tsuru, and H. Asahi: Proc. 16th Int. Offshore Polar Eng. Conf., Lisbon, 2007, pp. 2949–54.

  4. G. Shigesato, Y. Shinohara, T. Hara, M. Sugiyama, and H. Asahi: Proc. 16th Int. Offshore Polar Eng. Conf., Lisbon, 2007, pp. 2983–87.

  5. D.B. Lillig: Proc. 18th Int. Offshore Polar Eng. Conf., Vancouver, 2008, pp. 1–12.

  6. M.W. Hukle, B.D. Newbury, D.B. Lillig, J.J. Regina, and A.M. Horn: Proc. 27th Int. Conf. on Offshore Mech. and Arctic Eng., Estoril, 2008, pp. 16–19.

  7. N. Ishikawa, H. Sueyoshi, and N. Shikanai: Proc. 19th Int. Offshore Polar Eng. Conf., Osaka, 2009, pp. 43–49.

  8. K. Nagai, Y. Shinohara, S. Sakamoto, E. Tsuru, and H. Asahi: Proc. 19th Int. Offshore Polar Eng. Conf., Osaka, Japan, 2009, pp. 56–60.

  9. T. Hara, Y. Shinohara, Y. Terada, H. Asahi, and N. Doi: Proc. 19th Int. Offshore Polar Eng. Conf., Osaka, Japan, 2009, pp. 73–79.

  10. D. Hull and D.J. Bacon: Introduction to Dislocations, 5th ed., Elsevier Ltd., Amsterdam, 2011.

    Google Scholar 

  11. H. Igari, H. Nakamura, and S. Okaguchi: Proc. 21th Int. Offshore Polar Eng. Conf., Hawaii, 2011, pp. 569–74.

  12. T. Hara, Y. Shinohara, Y. Hattori, T. Muraki, and N. Doi: Proc. 21th Int. Offshore Polar Eng. Conf., ISOPE, Hawaii, 2011, pp. 575–80.

  13. H.K. Sung, D.H. Lee, S,Y. Shin, S. Lee, Y. Ro, C.S. Lee, and B. Hwang: Metall. Mater. Trans. A, 2015, vol. 46A, pp. 3989–98.

    Article  Google Scholar 

  14. H.K. Sung, D.H. Lee, S. Lee, H.S. Kim, Y. Ro, C.S. Lee, B. Hwang, and S.Y. Shin: Metall. Mater. Trans. A, 2016, vol. 47A, pp. 2726–38.

    Article  Google Scholar 

  15. J. Hu, L.-X. Du, J.-J. Wang, C.-R. Gao, T.-Z. Yang, A.-Y. Wang, and R.D.K. Misra: Metall. Mater. Trans. A, 2013, vol. 44A, pp. 4937–47.

    Article  Google Scholar 

  16. V. Colla, M. Desanctis, A. Dimatteo, G. Lovicu, and R. Valentini: Metall. Mater. Trans. A, 2011, vol. 41A, pp. 2781–93.

    Article  Google Scholar 

  17. B. Hwang, C.G. Lee, and S. Lee: Mater. Sci. Forum, 2010, vol. 638-642, pp. 3266–71.

    Article  Google Scholar 

  18. B. Hwang, Ph.D. Dissertation, Pohang University of Science and Technology, Pohang, 2004.

  19. T. Araki: Atlas for Bainitic Microstructures, ISIJ, Tokyo, 1992, pp. 1–100.

    Google Scholar 

  20. G. Krauss and S.W. Thompson: ISIJ Int., 1995, vol. 35, pp. 937–45.

    Article  Google Scholar 

  21. S.W. Thompson, D.J. Colvin, and G. Krauss: Metall. Trans. A, 1990, vol. 21A, pp. 1493–1507.

    Article  Google Scholar 

  22. F.S. LePera: Metallography, 1979, vol. 12, pp. 263–68.

    Article  Google Scholar 

  23. V. Randle and O. Engler: Introduction to Texture Analysis, CRC Press, Boca Raton, USA, 2014, pp. 153–88.

    Google Scholar 

  24. C. Capdevila, F.G. Caballero, and C. Garcia de Andres: ISIJ Int., 2003, vol. 42, pp. 894–902.

    Article  Google Scholar 

  25. K.W. Andrew: JISI, 1965, vol. 203, pp. 721–27.

    Google Scholar 

  26. C.Y. Kung and J.J. Raymond: Metall. Trans. A, 1982, vol. 13A, pp. 328–31.

    Article  Google Scholar 

  27. D.P. Koistinen and R.E. Marburger: Acta Metall., 1959, vol. 7, pp. 59–60.

    Article  Google Scholar 

  28. M. Calcagnotto, Y. Adachi, D. Ponge, and D. Raabe: Acta Mater., 2011, vol. 59, pp. 658–70.

    Article  Google Scholar 

  29. T. Sourmail and V. Smanio: Acta Mater., 2013, vol. 61, pp. 2639–48.

    Article  Google Scholar 

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Acknowledgment

This work was supported by the Technology Innovation Program (Grant Nos. 100400-25 and 10044574) funded by the Ministry of Trade, Industry, and Energy (MOTIE), Korea.

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Correspondence to Byoungchul Hwang.

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Manuscript submitted August 1, 2017.

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Lee, D.H., Sohn, S.S., Song, H. et al. Effects of Start and Finish Cooling Temperatures on the Yield Strength and Uniform Elongation of Strain-Based API X100 Pipeline Steels. Metall Mater Trans A 49, 4536–4543 (2018). https://doi.org/10.1007/s11661-018-4738-5

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  • DOI: https://doi.org/10.1007/s11661-018-4738-5

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