Korean Journal of Materials Research (한국재료학회지)

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

DOI QR Code

Effect of Interstitial Elements on Ductile-Brittle Transition Behavior of Austenitic Fe-18Cr-10Mn-2Ni Alloys

오스테나이트계 Fe-18Cr-10Mn-2Ni 합금의 연성-취성 천이 거동에 미치는 침입형 원소의 영향

  • Hwang, Byoungchul (Department of Materials Science and Engineering, Seoul National University of Science and Technology)
  • 황병철 (서울과학기술대학교 신소재공학과)
  • Received : 2013.09.29
  • Accepted : 2013.10.30
  • Published : 2013.11.27
Download PDF
⟨ Previous Next ⟩

Abstract

The effect of interstitial elements on the ductile-brittle transition behavior of austenitic Fe-18Cr-10Mn-2Ni alloys with different nitrogen and carbon contents was investigated in this study. All the alloys exhibited ductile-brittle transition behavior because of unusual low-temperature brittle fracture, even though they have a faced-centered cubic structure. With the same interstitial content, the combined addition of nitrogen and carbon, compared to the sole addition of nitrogen, improved the low-temperature toughness and thus decreased the ductile-brittle transition temperature (DBTT) because this combined addition effectively enhances the metallic component of the interatomic bonds and is accompanied by good plasticity and toughness due to the increased free electron concentration. The increase in carbon content or of the carbon-to-nitrogen ratio, however, could increase the DBTT since either of these causes the occurrence of intergranular fracture that lead to the deterioration of the toughness at low temperatures. The secondary ion mass spectroscopy analysis results for the observation of carbon and nitrogen distributions confirms that the carbon and nitrogen atoms were significantly segregated to the austenite grain boundaries and then caused grain boundary embrittlement. In order to successfully develop austenitic Fe-Cr-Mn alloys for low-temperature application, therefore, more systematic study is required to determine the optimum content and ratio of carbon and nitrogen in terms of free electron concentration and grain boundary embrittlement.

Keywords

References

  1. M. O. Speidel, C. Kowanda, M. Diener, HNS 2003 (High Nitrogen Steels), Schaffhausen, Switzerland, Institute of Metallurgy, ETH, Zurich (2003).
  2. N. Akdut, B. C. De Cooman, H. S. Kim, Proceedings of 1st Int. Conf. Interstitially Alloyed Stees (IAS 2008), Pohang, Korea (2008).
  3. J. Bernauer, G. Saller, M. O. Speidel, in Proceedings of 7th Int. Conf. High Nitrogen Steels, eds. N. Akdut, B. C. De Cooman, J. Foct, (GRIPS media GmbH, Ostend, Belgium, Sept. 2004). p. 529.
  4. V. G. Gavriljuk, B. D. Shanina, H. Berns, Acta Mater., 56, 5071 (2008). https://doi.org/10.1016/j.actamat.2008.06.021
  5. V. G. Gavriljuk, B. D. Shanina, H. Berns, Mater. Sci. Eng., A, 481-482, 707 (2008). https://doi.org/10.1016/j.msea.2006.11.186
  6. F. Schmalt, H. Berns, V. G. Gavriljuk, in Proc. 7th Int. Conf. High Nitrogen Steels (GRIPS media GmbH, Ostend, Belgium, Sept. 2004) p. 437.
  7. H-Y. Ha, T-H. Lee, C-S. Oh, S-J. Kim, Scr. Mater., 61, 121 (2009). https://doi.org/10.1016/j.scriptamat.2009.03.018
  8. T-H. Lee, E. Shin, C-S. Oh, H-Y. Ha, S-J. Kim, Acta Mater., 58, 3173 (2010). https://doi.org/10.1016/j.actamat.2010.01.056
  9. L. Mujica, S. Weber, W. Theisen, in Proceedings of 1st International Conference on High Manganese Steels (HMnS 2011), ed. Y-K. Lee (Yonsei University, Seoul, Korea, 2011) p. B-20.
  10. V. G. Gavriljuk, B. D. Shanina, H. Berns, Acta Mater., 48, 3879 (2000). https://doi.org/10.1016/S1359-6454(00)00192-0
  11. P. Mullner, C. Solenthaler, P. J. Uggowitzer, M. O. Speidel, Acta Metall. Mater., 42, 2211 (1994). https://doi.org/10.1016/0956-7151(94)90300-X
  12. Y. Tomota, Y. Xia, K. Inoue, Acta Mater., 46, 1577 (1998). https://doi.org/10.1016/S1359-6454(97)00350-9
  13. P. J. Uggowitzer, R. Magdowski, M. O. Speidel, ISIJ Int., 26, 901 (1996).
  14. B. Hwang, T-H. Lee, Kor. J. Mater. Res., 23, 483 (2013). https://doi.org/10.3740/MRSK.2013.23.9.483
  15. M. O. Speidel, M. Zheng-Cui, in HNS 2003 - High Nitrogen Steels (Institute of Metallurgy, ETH, Zurich, 2003). p. 63
  16. B. Hwang, T-H. Lee, S-J. Park, C-S. Oh, S-J. Kim, Mater. Sci. Eng., A, 528, 7257 (2011). https://doi.org/10.1016/j.msea.2011.06.025