Corrosion Science and Technology

The Corrosion Science Society of Korea (한국부식방식학회)
권호 표지
DOI QR코드

DOI QR Code

The Effect of Welding Method on the Electrochemical Behavior of Austenitic Stainless Steel Sheet

  • Kim, Young-Hune (Pohang University of Science and Technology Department of Materials Science and Engineering) ;
  • Kim, Kyoo-Young (Pohang University of Science and Technology Department of Materials Science and Engineering)
  • Received : 2010.03.25
  • Accepted : 2010.06.15
  • Published : 2010.06.01
Download PDF
⟨ Previous Next ⟩

Abstract

The corrosion of the flexible tube in the automobile exhaust system is caused by the ambient water and chloride ions. Since welding is one of the key processes for the flexible tube manufacturing, it is required to select a proper welding method to prevent the flexible tube corrosion and to increase its lifetime. There are many studies about the efficiency of the welding method, but no systematic study is performed for the effect of welding method on the corrosion property of the austenitic stainless weldment. The aim of the present study is to provide information on the effect of two different welding methods of TIGW (tungsten inert gas welding) and PAW (plasma arc welding) on the corrosion property of austenitic stainless steel weldment. Materials used in this study were two types of the commercial austenitic stainless steel, STS321 and XM15J1, which were used for flexible tube material for the automotive exhaust system. Microstructure was observed by using optical microscopy (OM) and scanning electron microscopy (SEM). To evaluate the corrosion behavior, potentiodynamic and potentiostatic tests were performed. The chemical state of the passive film was analyzed in terms of XPS depth profile. Metallurgical analysis show that the ferrite content in fusion zone of both STS321 and XM15J1 is higher when welded by PAW than by TIGW. The potentiodynamic and potentiostatic test results show that both STS321 and XM15J1 have higher transpassive potential and lower passive current density when welded by PAW than by TIGW. XPS analysis indicates that the stable $Cr_2O_3$ layer at the outermost layer of the passive film is formed when welded by PAW. The result recommends that PAW is more desirable than TIGW to secure corrosion resistance of the flex tube which is usually made of austenitic stainless steel.

Keywords

References

  1. H.H. Uhlig and R.W. Revie, Corrosion and Corrosion Control, N.Y. Wiley (1985).
  2. K.Asami. Corris. Sci., 18, 151 (1978). https://doi.org/10.1016/S0010-938X(78)80085-7
  3. K. Hashimoto, Corris. Sci., 19, 3 (1979). https://doi.org/10.1016/0010-938X(79)90003-9
  4. M. G. PUJAR, PhD thesis, Indian Institute of Technology. Bombay (1996).
  5. Welding of Stainless Steel, Korean Iron and Steel Association, Seoul, p. 61 (1991).
  6. J. M. David and S. A. David, Weld. J., 67. 95 (1988).
  7. Mizukami H., Suzuki T., and Umeda T., Tetsu To Hagane, Japan, 77, 134 (1991).
  8. M. Sakashita and N. Sato, Passivity of Metals, p. 740 (1978).
  9. Y. C. Lu and C. R. Clayton, J. Chin. Soc. Corr. Prot., 18. 30 (1988).
  10. C. R. Clayton and Y. C. Lu, J. Electrochem. Soc., 133. 2465 (1986). https://doi.org/10.1149/1.2108451
  11. A. R. Brooks, C. R. Clayton, K. Doss, and Y. C. Lu, J. Electrochem. Soc., 133. 2456 (1986).
  12. Y. C. Lu, C. R. Clayton, and A. R. Brooks, Corros. Sci., 29. 863 (1989). https://doi.org/10.1016/0010-938X(89)90058-9
  13. I. Olefjord, B. Brox, and U. Jelvestam, J. Electrochem. Soc., 132. 2854 (1985). https://doi.org/10.1149/1.2113683
  14. P. Marcus and J. M. Grimal, Corros. Sci., 33, 805 (1992). https://doi.org/10.1016/0010-938X(92)90113-H
  15. W. P. Yang, D. Costa, and P. Marcus, J. Electrochem. Soc., 141, 2669 (1994). https://doi.org/10.1149/1.2059166
  16. I. Olefjord and L. Wegrelius, Corros. Sci., 31, 89 (1990). https://doi.org/10.1016/0010-938X(90)90095-M
  17. L. Wegrelius, F. Falkenberg, and I. Olefjord, J. Electrochem. Soc., 146, 1397 (1999). https://doi.org/10.1149/1.1391777
  18. P. E. Manning, Corrosion, 36, 246 (1980). https://doi.org/10.5006/0010-9312-36.5.246
  19. C. T. Liu and J. K. Wu, Corros. Sci., 49. 2198 (2007). https://doi.org/10.1016/j.corsci.2006.10.032