Corrosion Science and Technology

The Corrosion Science Society of Korea (한국부식방식학회)
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Sensitivity to Intergranular Corrosion According to Heat Treatment of 304L Stainless Steel

304L 스테인리스강의 열처리에 따른 입계부식민감도 연구

  • 장형민 (한국원자력연구원 안전재료기술개발부) ;
  • 김동진 (한국원자력연구원 안전재료기술개발부) ;
  • 김홍표 (한국원자력연구원 안전재료기술개발부)
  • Received : 2020.01.10
  • Accepted : 2020.02.26
  • Published : 2020.02.28
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Abstract

Even though 304 low-carbon (304L) stainless steel was developed to enhance the resistance to intergranular corrosion and stress corrosion cracking, it is occasionally subject to degradation in harsh environments. The degree of sensitization (DOS) of 304L stainless steel was studied as a function of sensitization using a double-loop electrochemical potentiokinetic reactivation (DL-EPR) method. Sensitizing heat treatment was performed in an Ar atmosphere at 500℃, 600℃, and 700℃, with heat treatment times varying from 0 to 96 h. DOS was measured by the ratio of the peak current density value of the forward scan to that of the reverse scan. After the EPR experiment, the specimen surface was observed by scanning electron microscopy and energy dispersive spectroscopy. The DOS of the specimens heat-treated at 600℃ increased with heat treatment times up to 48 h and then decreased due to a self healing effect. The DOS was higher in specimens heat-treated at 600℃ than those at 500℃ or 700℃. Corrosion of the sensitized specimens occurred mainly at the δ-γ phase boundary. The corrosion morphology at the δ-γ phase boundary changed with sensitizing heat-treatment conditions due to differences in chromium activity in γ austenite and δ ferrite.

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References

  1. Coil, & Bar - AMS 5513, 5511, 5647, 304 Stainless steel and 304L Stainless Steel Sheet. https://www.upmet.com/products/stainless-steel/304304l
  2. L. Ernest and C. L. Briant, Metall. Trans. A, 15A, 794 (1984).
  3. J. S. Armijo, Corrosion, 24, 24 (1968). https://doi.org/10.5006/0010-9312-24.1.24
  4. L. Tan, R. E. Stoller, K. G. Field, Y. Yang, H. Nam, D. Morgan, B. D. Wirth, M. N. Gussev, and J. T. Busby, JOM, 68, 517 (2016). https://doi.org/10.1007/s11837-015-1753-5
  5. A. H. Tuthill, Weld. J., 5, 36 (2005).
  6. W. E. White, Mater. Charact., 28, 349 (1992). https://doi.org/10.1016/1044-5803(92)90021-9
  7. A. J. Sedriks, Corrosion of Stainless Steels, 2nd ed., p. 18, John Wiley & Sons, New York (1996).
  8. R. M. Davision, T. DeBold, and M. J. Johnson, Metals Handbook, Vol. 13, Corrosion, 9th ed., p. 547, ASM, Metals Park, OH (1987).
  9. P. I. Williams and R. G. Faukner, J. Mater. Sci., 22, 3537 (1987). https://doi.org/10.1007/BF01161455
  10. D. E. Jiang and Emily A. Carter, Phycal Review B, 67, 214103 (2003). https://doi.org/10.1103/PhysRevB.67.214103