Microstructure Evolution and σ-Phase Precipitation Kinetics of 2507 Duplex Stainless Steel Aging at 850°C

Abstract:

A commercial 2507 duplex stainless steel with different solution treatments followed by aging at 850°C has been investigated. At the early aging time of 850°C, the σ-phase precipitate was predominantly distributed at the δ/γ interface, as the isothermal aging time was increased to 150 min, more σ-phase precipitate formed in ferrite and became coarser by a eutectoid reaction δσ+γ₂. The amount of δ-ferrite decreased rapidly at the beginning of aging for 80 minutes, increasing solution treatment temperature from 1060°C to 1230°C delayed decomposition of δ-ferrite due to lowering σ-phase formation element (Cr). The reaction rate K and σ-phase precipitation rate were lowered by increasing solution treatment temperature from 1060°C to 1230°C.

• Periodical: Advanced Materials Research (Volume 711)
• Pages: 87-90
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.711.87
• Online since: June 2013
• Authors: Yin Hui Yang
• Keywords: Duplex Stainless Steel, Precipitation Rate, Solution Treatment, σ-Phase

References

[1] Nilsson JO: Mater Sci Technol Vol. 8 (1992), p.700.

[2] L. Weber, P.J. Uggowitzer: Mater. Sci. Eng. A Vol. 242 (1998), p.222.

[3] P.D. Southwick, R.W.K. Honeycombe: Metal Sci. Vol. 16 (1982), p.475.

[4] Andrews KW: Nature Vol. 164 (1949), p.1015.

[5] Johnson E, Kim YJ, Chumbley LS, Gleeson B: Scripta Mater Vol. 50 (2004), p.1354.

[6] G. Sasikala, S.K. Ray, S.L. Mannan: Mater. Sci. Eng. A Vol. 359 (2003), p.86.