DOI QR코드

DOI QR Code

High-Temperature Mechanical Behaviors of Type 316L Stainless Steel

Type 316L 스테인리스강의 고온 기계적 거동

  • 김우곤 (한국원자력연구원, 신소재융합기술연구부) ;
  • 이형연 (한국원자력연구원, 다목적 계통기술개발부)
  • Received : 2020.05.22
  • Accepted : 2020.06.18
  • Published : 2020.06.30

Abstract

High-temperature mechanical behaviors of Type 316L stainless steel (SS), which is considered as one of the major structural materials of Generation-IV nuclear reactors, were investigated through the tension and creep tests at elevated temperatures. The tension tests were performed under the strain rate of 6.67×10-4 (1/s) from room temperature to 650℃, and the creep tests were conducted under different applied stresses at 550℃, 600℃, 650℃, and 700℃. The tensile behavior was investigated, and the modeling equations for tensile strengths and elongation were proposed as a function of temperature. The creep behavior was analyzed in terms of various creep equations: Norton's power law, modified Monkman-Grant relation, damage tolerance factor(λ), and Z-parameter, and the creep constants were proposed. In addition, the tested tensile and creep strengths were compared with those of RCC-MRx. Results showed that creep exponent value decreased from n=13.55 to n=7.58 with increasing temperature, λ = 6.3, and Z-parameter obeyed well a power-law form of Z=5.79E52(σ/E)9.12. RCC-MRx showed lower creep strength and marginally different in creep strain rate, compared to the tested results. Same creep deformation was operative for dislocation movement regardless of the temperatures.

Keywords

References

  1. www.aksteel.com, 2007, "304/304L Stainless Steel Data Sheet," 7100-0096 7/07, AK Steel Corporation, OH USA.
  2. www.outokumpu.com, 2014, "Outokumpu High Performance Stainless," 1087EN, Bannockburn USA.
  3. Afcen RCC-MRx Code, 2015, Section III-Tome 1-Subsection Z: Technical Appendics, France.
  4. Afcen RCC-MRx Code, 2018, Section III-Tome 2: Materials, France.
  5. ASTM E8M-17, 2017, "Standard test method for Tension Testing of Metallic Materials," ASTM Standard.
  6. Kim, J.M., Kim, W.G. and Kim, M.C., 2019, "Evaluation of Creep Behaviors of Alloy 690 Steam Generator Tubing Material," Trans. of KPVP, Vol. 14, No.1, pp. 64-70. doi: http://dx.doi.org/10.20466/ KPVP.2019.15.2.064.
  7. ASTM E139-17, 2017, "Standard Test Method for Conducting Creep, Creep-Rupture And Stress Rupture Tests of Metallic Materials," ASTM Standard.
  8. Kim, W.G. Park, J.Y. Ekaputra, I.M.W., Kim, S.J., Kim, M.H. and Kim, Y.W., 2015, "Creep Deformation and Rupture Behavior of Alloy 617," Eng. Fail. Anal., Vol. 58, pp. 441-451. https://doi.org/10.1016/j.engfailanal.2015.07.041
  9. Dobes, F. and Milicka,K., 1976, "The Relation between Minimum Creep Rate and Time to Fracture," Met. Sci. Vol. 10, pp. 382-384. https://doi.org/10.1080/03063453.1976.11683560
  10. Monkman, F.C. and Grant, N.J., 1956, "An Empirical Relationship Between Rupture Life and Minimum Creep Rate in Creep Rupture Tests," ASTM Proc., Vol. 56, pp. 593-620.
  11. Guguloth, K. and Roy, N., 2017, "Creep Deformation Behavior of 9CrMoVNb (ASME Grade 91) Steel," Mater. Sci. Eng. A., Vol. 680, pp. 386-404.
  12. Choudhary, B.K., 2013, "Tertiary Creep Behaviour of 9Cr-1Mo Ferritic Steel," Mater. Sci. Eng. A., Vol. 585, pp. 1-9. https://doi.org/10.1016/j.msea.2013.07.026
  13. B.K. Choudhary, E. Issac Samual, 2011, "Creep Behavior of Modified 9Cr-1Mo Ferritic Steel," J. Nucl. Mater, 412, pp. 82-89. https://doi.org/10.1016/j.jnucmat.2011.02.024
  14. Benz, J.K. Carroll, L.J., Wright, J.K., Wright, R.N. and Lillo, T.M., 2014, "Threshold Stress Creep Behavior of Alloy 617 at Intermediate Temperature," Metall. Mater. Trans. A, Vol. 45A, pp. 3010-3022. https://doi.org/10.1007/s11661-014-2244-y