Influence of Alloying on α-αʹ Phase Separation in Duplex Stainless Steels
Thermal embrittlement caused by phase transformations in the temperature range of 204–538 °C limits the service temperature of duplex stainless steels. The present study investigates a set of wrought (2003, 2101, and 2205) and weld (2209-w and 2101-w) alloys in order to better understand how alloying elements affect thermal embrittlement. Samples were aged at 427 °C for up to 10,000 h. The embrittlement and thermal instability were assessed via nanoindentation, impact toughness testing, and atom probe tomography (APT). Results demonstrate that the spinodal amplitude is not an accurate predictor of mechanical degradation, and that nanoindentation within the ferrite grains served as a reasonable approximate for the embrittlement behavior. Compositionally, alloys with a lower concentration of Cr, Mo, and Ni were found to exhibit superior mechanical properties following aging.
KeywordsDuplex stainless steels Spinodal decomposition Embrittlement
APT was conducted at Oak Ridge National Laboratory’s Center for Nanophase Materials Sciences (CNMS), which is a U.S. DOE Office of Science User Facility.
- 2.H.D. Solomon, T.M. Devine, Duplex Stainless Steels: A Tale of Two Phases. American Society for Metals (1982)Google Scholar
- 3.J. Charles, Duplex stainless steels, a review after DSS’07 in Grado, presented at the Revue de Métallurgie, (2008)Google Scholar
- 4.J. Lai, S.H. Shek, K.H. Lo, Stainless Steels : An Introduction and Their Recent Developments. (Bentham Science Publishers, 2012)Google Scholar
- 6.M. Guttman, Intermediate temperature aging of duplex stainless steels. A Review, (1991)Google Scholar
- 11.W. Guo, D.A. Garfinkel, J.D. Tucker, D. Haley, G.A. Young, and J.D., Poplawsky, An atom probe perspective on phase separation and precipitation in duplex stainless steels. J. Nanotechnol. (2016)Google Scholar
- 12.G.A. Young, J.D Tucker, N Lewis, E. Plesko, P. Sander, Assessment of lean grade duplex stainless steels for nuclear power applications. Proc. 15th International Conference Environment Degradation Materials Nuclear Power Systematics-Water React (2011)Google Scholar