Hostname: page-component-848d4c4894-xfwgj Total loading time: 0 Render date: 2024-07-06T13:29:45.091Z Has data issue: false hasContentIssue false
  • English
  • Français

A study on pitting initiation mechanism of super-austenitic stainless steel weld in chloride environment

Published online by Cambridge University Press:  27 September 2016

Sung Jin Kim  and
Seung Gab Hong
Sung Jin Kim*
Affiliation:
Department of Advanced Materials Engineering, Sunchon National University, Suncheon 540-742, Republic of Korea
Seung Gab Hong
Affiliation:
POSCO Steel Solution Marketing Division, Pohang 790-704, Korea
*
a)Address all correspondence to this author. e-mail: sjkim56@sunchon.ac.kr
Get access

Abstract

There has been controversy over the localized corrosion mechanism of super-austenitic stainless steel weld due mainly to the lack of effective evaluation technique for identification of corrosion nucleation site in weld. For this reason, an electrochemical polarization method followed by an observation of microstructure using the back-scattered electron mode in field emission-scanning electron microscopy is used. To clarify the localized corrosion mechanism, energy dispersive spectroscopy line profile analyzed by transmission electron microscopy is additionally utilized. It clearly reveals that the selective corrosion is preferentially initiated around the σ-phase precipitated in the interdendritic region in weld. The local depletion of Cr and Mo around the σ-phase can be partly replenished by the diffusion of the elements into the depleted area during the subsequent heat treatment at 1180 °C.

Keywords

steelcorrosionwelding
Type
Articles
Information
Journal of Materials Research , Volume 31 , Issue 21 , 14 November 2016 , pp. 3345 - 3351
Check for updates
Copyright
Copyright © Materials Research Society 2016 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

Contributing Editor: Jürgen Eckert

References

REFERENCES

Kim, S.T., Kim, S.Y., Lee, I.S., Park, Y.S., Shin, M.C., and Kim, Y.S.: Effects of shielding gases on the microstructure and localized corrosion of tube-to-tube sheet welds of super austenitic stainless steel for seawater cooled condenser. Corros. Sci. 53, 2611 (2011).Google Scholar
Mori, G. and Bauernfeind, D.: Pitting and crevice corrosion of superaustenitic stainless steels. Mater. Corros. 55, 164 (2004).CrossRefGoogle Scholar
Dupont, J.N.: Microstructural development and solidification cracking susceptibility of a stabilized stainless steel. Weld. J. 8, 253 (1999).Google Scholar
Vilpas, M., Karppi, R., Kuronen, M., and Kyrolainen, A.: Pitting corrosion resistance of austenitic stainless steels welded by high-speed laser process. In Proc. Third European Congress 3, Properties and Performances (Italy, 1999); p. 111.Google Scholar
Banovic, S.W., Dupoint, J.N., and Marder, A.R.: Dilution and microsegregation in dissimilar metal welds between super austenitic stainless steel. Sci. Technol. Weld. Joining 7, 374 (2002).Google Scholar
Nam, S.K., Park, S.J., Na, H.S., and Kang, C.Y.: Effect of welding thermal cycle on microstructure and pitting corrosion property of multi-pass weldment of super duplex stainless steel. J. Weld. Joining 28, 18 (2010).CrossRefGoogle Scholar
Calliari, I., Zanesco, M., and Ramous, E.: Influence of isothermal aging on secondary phases precipitation and toughness of a duplex stainless steel SAF 2205. J. Mater. Sci. 41, 7643 (2006).Google Scholar
Jang, S.H., Kim, S.T., Lee, I.S., and Park, Y.S.: Effect of shielding gas composition on phase transformation and mechanism of pitting corrosion of hyper duplex stainless steel welds. Mater. Trans. 52, 1228 (2011).Google Scholar
Park, C.J., Rao, V.S., and Kwon, H.S.: Effects of sigma phase on the initiation and propagation of pitting corrosion of duplex stainless steel. Corrosion 61, 76 (2005).Google Scholar
Wilms, M.E., Gadgil, V.J., Krougmen, J.M., and Ijsseling, F.P.: The effect of σ-phase precipitation at 800 °C on the corrosion resistance in sea-water of a high alloyed duplex stainless steel. Corrs. Sci. 36, 871 (1994).Google Scholar
ASTM G48: Standard Test Methods for Pitting and Crevice Corrosion Resistance of Stainless Steels and Related Alloys by Use of Ferric Chloride Solution (ASTM International, West Conshohocken, 2011).Google Scholar
ASTM G151: Standard Practice for Exposing Nonmetallic Materials in Accelerated Test Devices that Use Laboratory Light Sources (ASTM International, West Conshohocken, 2011).Google Scholar
Espy, R.H.: Weldability of nitrogen-strengthened stainless steels. Weld. J. 61, 149 (1982).Google Scholar
Garner, A.: The effect of autogenous welding on chloride pitting corrosion in austenitic stainless steels. Weld. J. 62, 27 (1983).Google Scholar
Brooks, J.A., Williams, J.C., and Thompson, A.W.: Microstructural origin of the skeletal ferrite morphology of austenitic stainless steel welds. Met. Trans. 14(A), 1271 (1983).CrossRefGoogle Scholar
Kim, S.J. and Hong, S.G.: Evaluation of localized corrosion resistance and clarification of the corrosion mechanism of super austenitic stainless steel weld. POSCO Technical Report 20(1), (2015).Google Scholar
Moayed, M.H. and Newman, R.C.: Evolution of current transients and morphology of metastable and stable pitting on stainless steel near the critical pitting temperature. Corros. Sci. 48, 1004 (2006).Google Scholar
Frankel, G.S.: Pitting corrosion of metals. J. Electrochem. Soc. 145, 2186 (1998).CrossRefGoogle Scholar
Jang, B.S., Moon, I.J., Lim, M.J., Kim, S.C., Kim, S.S., Lee, J.W., Park, H.W., and Koh, J.H.: Heat treatment effect on super duplex stainless steel UNS S32750 FCA multipass welds. J. Weld. Join. 32, 174 (2014).Google Scholar
Glover, T.J.: Application of stainless steels in chemical plant corrosive environments. Anti-Corros. Methods Mater. 29, 11 (1982).Google Scholar
John Sedriks, A.: Corrosion of stainless steels, 2nd ed. (John Wiley & Sons, Inc., Hoboken, 1996).Google Scholar
Wang, Y.Q., Han, J., Wu, H.C., Yang, B., and Wang, X.T.: Effect of sigma phase precipitation on the mechanical and wear properties of Z3CN20.09M cast duplex stainless steel. Nucl. Eng. Des. 259, 1 (2013).Google Scholar
Hsieh, C.C. and Wu, W.: Overview of intermetallic sigma (σ) phase precipitation in stainless steels. ISRN Metall. 2012, 1 (2012).Google Scholar
Paulraj, P. and Garg, R.: Effect of intermetallic phases on corrosion behavior and mechanical properties of duplex stainless steel and super-duplex stainless steel. Adv. Sci. Technol. Res. J. 9, 87 (2015).Google Scholar
Deng, B., Wang, Z., Jiang, Y., Wang, H., Gao, J., and Li, J.: Evaluation of localized corrosion in duplex stainless steel aged at 850 °C with critical pitting temperature measurement. Electrochim. Acta 54, 2790 (2009).Google Scholar