DOI QR코드

DOI QR Code

Study on VHCF Fatigue Behaviors and UNSM Effects of Hydrogen Attacked STS 316L

수소취화된 스테인리스강 316L의 VHCF(Very High Cycle Fatigue) 피로특성과 UNSM 효과에 관한 연구

  • 남승훈 (한국표준과학연구원) ;
  • 백운봉 (한국표준과학연구원) ;
  • 서창민 (경북대학교 기계공학부, 대구기계부품연구원) ;
  • 편영식 (선문대학교 기계공학부)
  • Received : 2017.01.31
  • Accepted : 2017.09.06
  • Published : 2017.11.01

Abstract

This study was conducted to investigate the material properties of stainless steel 316L specimens of untreated and UNSM treated material, hydrogen attacked material(100 bar, $300^{\circ}C$ at 120 h) and UNSM treated hydrogen attacked material at room temperature. Results demonstrated that the hydrogen attacked materials showed a tendency toward a slightly decreased fatigue strength, while the hydrogen embrittlement effect was smaller than the S-N curve of conventional untreated material. As compared to untreated material, the fatigue limit of the UNSM treated material increased by 43.8%, while it was 57.1% higher in the UNSM treated hydrogen attacked material than in untreated hydrogen attacked material. The plastic deformation layer was ${\sim}152{\mu}m$ thick, as confirmed by maps showing the level of local plastic deformation affected by the UNSM treatment in three ways: an image quality map, inverse pole figure map, and kernel average misorientation map captured via electron back scatter diffraction. Owing to hydrogen embrittlement, about 90% of surface cracks were smaller than the average grain size of $35{\mu}m$.

본 연구는 실온에서 미처리재와 UNSM처리재, 수소취화재(100 bar, $300^{\circ}C$에서 120 h) 및 이 수소취화재의 UNSM처리재의 스테인리스강 316L 시험편의 재료특성파악을 위한 실험을 실시하였다. 여기서 수소취화재는 기존의 미처리재의 S-N곡선보다 피로강도가 약간 감소하는 경향을 나타내었으며, 수소취화효과는 적게 나타났다. 미처리재에 비해서 UNSM처리재의 피로한도는 약 43.8 % 상승하였고, 수소취화재의 UNSM처리재는 수소취화재보다 약 57.1 % 상승하는 경향을 나타내었다. EBSD에 의한 IQ, IPF 및 KAM 맵에서 UNSM처리 후, 이 처리의 영향을 받는 나노 입자 표면층의 두께는 약 $152{\mu}m$이다. 그러나 세 가지 맵에서 수소취화의 깊이 영향을 정량적으로 평가할 수 없었다. 시험편상에서 발생하는 표면균열은 수소취화의 영향으로 평균입경($35{\mu}m$)보다 작은 균열의 비율이 약 90 %를 차지하였다.

Keywords

References

  1. Shin, H. S., Kim, K. H., Back, U. B. and Nahm, S. H., 2011, "Development of Evaluation Technique for Hydrogen Embrittlement Behavior of Metallic Materials Using In-situ SP Testing under Pressurized Hydrogen Gas Conditions," Trans. Korean Soc. Mech. Eng. A, Vol. 35, No. 11, pp. 1377-1382. https://doi.org/10.3795/KSME-A.2011.35.11.1377
  2. Suh, C. M., Nahm, S. H., Kim, J. H. and Pyoun, Y. S., 2016, "A Study on the VHCF Fatigue Behaviors of Hydrogen Attacked Inconel 718 Alloy," Trans. Korean Soc. Mech. Eng. A, Vol. 40, No. 7, pp. 637-646. https://doi.org/10.3795/KSME-A.2016.40.7.637
  3. Zinbi, A. and Bouchou, A., 2010, "Delayed Cracking in 301 Austenitic Steel After Bending Process: Martensitic Transformation and Hydrogen Embrittlement Analysis," Engineering Failure Analysis 17, pp. 1028-1037. https://doi.org/10.1016/j.engfailanal.2009.11.007
  4. Bechtle, S., Kumar, M., Somerday, B. P., Launey, M. E. and Ritchie, R. O., 2009, "Grain-boundary Engineering Markedly Reduces Susceptibility to Intergranular Hydrogen Embrittlement in Metallic Materials," Acta Materialia 57, pp. 4148-4157. https://doi.org/10.1016/j.actamat.2009.05.012
  5. Cotterill, P. J. and King, J. E., 1991, "Hydrogen Embrittlement Contributions to Fatigue Crack Growth in a Structural Steel," International Journal of Fatigue 13, No. 6, pp. 447-452. https://doi.org/10.1016/0142-1123(91)90478-H
  6. Bruchhausen, M., Fischer, B., Ruiz, A., Gonzalez, S., Hahner, P. and Soller, S., 2015, "Impact of Hydrogen on the High Cycle Fatigue Behavior of Inconel 718; a Symmetric Push-pull Mode at Room Temperature," International Journal of Fatigue 70, pp. 137-145. https://doi.org/10.1016/j.ijfatigue.2014.09.005
  7. Kouters, M.H.M., Slot, H. M., Zwieten, W. van, Veer, J. van der, 2014, "The Influence of Hydrogen on the Fatigue Life of Metallic Leaf Spring Components in a Vacuum Environment," International Journal of Fatigue 59, pp. 309-314. https://doi.org/10.1016/j.ijfatigue.2013.09.013
  8. Karsch, T., Clausen, B. and Zoch, H. W., 2014, "Influence of Hydrogen and Deoxidation Technique on the Fatigue Behaviour of Steel SAE 52100 in the VHCF Regime," 6th International Conference on VHCF October 15-18, Chengdu, China.
  9. Suh, C. M., Lee, M. H. and Pyoun, Y. S., 2010, "Fatigue Characteristics of SKD-61 by Ultrasonic Nanocrystal Surface Modification Technology Under Static Load Variation," International Journal of Modern Physics B. 24, 15-16, pp. 2645-2650. https://doi.org/10.1142/S0217979210065404
  10. Suh, C. M., Song, G. H., Suh, M. S. and Pyoun, Y. S., 2007, "Fatigue and Mechanical Characteristics of Nanostructured Tool Steel by Ultrasonic Cold Forging Technology," Mater. Sci. Eng. A, 443, pp. 101-106. https://doi.org/10.1016/j.msea.2006.08.066
  11. Roland, T., Retraint, D., Lu, K. and Lu, J., 2006, "Fatigue Life Improvement Through Surface Nanostructuring of Stainless Steel by Means of Surface Mechanical Attrition Treatment," Scripta Mater, 54, pp. 1949-1954. https://doi.org/10.1016/j.scriptamat.2006.01.049
  12. Dai, K. and Shaw, L., 2008, "Analysis of Fatigue Resistance Improvements via Surface Severe Plastic Deformation," Int. J. Fatigue, 30, pp. 1398-1402. https://doi.org/10.1016/j.ijfatigue.2007.10.010
  13. Tian, J. W., Villegas, J. C., Yuan, W., Fielden, D., Shaw, L., Liaw, P. K. and Klarstrom, D. L., 2007, "A Study of the Effect of Nanostructured Surface Layers on the Fatigue Behaviors of a C-2000 Superalloy," Mater. Sci. Eng. A, pp. 164- 168.
  14. Wang, T., Wang, D. P., Liu, G., Gong, B. M. and Song, N. X., 2008, "Investigations on the Nanocrystallization of 40 Cr Using Ultrasonic Surface Rolling Processing," Appl. Surf. Sci, 255, pp. 1824-1828. https://doi.org/10.1016/j.apsusc.2008.06.034
  15. Gill, A., Telang, A., Mannava, S. R,. Qian, D., Pyoun, Y. S., Soyama, H. and Vasudevan, V. K., 2013, "Comparison of Mechanisms of Advanced Mechanical Surface Treatments in Nickel-based Superalloy," Materials Science & Engineering A, 576, pp. 346-355. https://doi.org/10.1016/j.msea.2013.04.021
  16. Pyun, Y. S., Kim, J. H., Suh, C. M., Cho, I. S., Oh, J. Y., Wang, Q. and Khan, M. K., 2014, "The Rotary Bending Fatigue and Ultrasonic Fatigue Performance of Ti-6Al-4V ELI and STA Alloys After Ultrasonic Nanocrystal Surface Modification Treatment," Int. Conf. on VHCF-6, China.
  17. Kitagawa, H., Takahashi, S., Suh, C. M. and Miyashita, S., 1979, "Quantitative Analysis of Fatigue Process: Micro-Cracks and Slip lines under Cyclic Strains," ASTM STP 678, pp. 420-449.
  18. Suh, C. M., Yuuki, R. and Kitagawa, H., 1985, "Fatigue Microcracks in a Low Carbon Steel," Fatigue Fract. Engng. Mater. Struct., 8-2, pp. 193- 203.
  19. Suh, C. M. and Kitagawa, H., 1987, "Crack Growth Behaviour of Fatigue Microcracks in Low Carbon Steels," Fatigue Fract. Engng. Mater. Struct., 9-6, pp. 409-424.
  20. Kitagawa, H., Nakasone, Y. and Shimodaira, M., 1985, "A Fracture Mechanics Study of the Corrosion Fatigue of a Structural Steel with a Surface Defect," Trans. of the JSME series A, Vol. 51-464, pp. 1026-1033.
  21. Nahm, S. H. and Suh, C. M., 1997, "Observation on the Growth Behavior of Small Surface Cracks Using Remote Measurement System," ASTM STP, 1318, pp. 71-84.
  22. Jung, H. G., 2011, "Hydrogen Embrittlement Phenomenon of Steel Materials," Journal of Korean Soc. Mech. Eng., Vol. 51, No. 11, pp. 42- 44.
  23. Suh, C. M., Suh M. S. and Hwang, N. S., 2011, "Growth Behaviours of Small Surface Fatigue Crack in AISI 304 Steel," Fatigue Fract. Engng. Mater. Struct., Vol. 35, No. 1, pp. 22-29.

Cited by

  1. Very High Cycle Fatigue Behaviors and Surface Crack Growth Mechanism of Hydrogen-Embrittled AISI 304 Stainless Steels vol.09, pp.04, 2018, https://doi.org/10.4236/msa.2018.94027