Microstructures and Mechanical Properties of Nano/Ultrafine-Grained N-Bearing, Low-Ni Austenitic Stainless Steels
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The nitrogen (N)-bearing austenitic stainless steels are new materials with interesting mechanical properties such as high strength and ductility, desirable toughness and work hardening, and good corrosion resistance. This work attempted to investigate the effect of N addition from 0.08 to 0.35 wt.% on grain refinement of the 201L austenitic stainless steel using the martensite thermomechanical process. This process was composed of cold rolling up to the thickness reduction of 90 % followed by reversion annealing at 800 °C for 60 and 1800 s. It was found that increasing N content resulted in an increase in the austenite grain size for short annealing duration (e.g. 60 s), but caused a decrease in the austenite grain size for long annealing duration (e.g. 1800 s). The smallest austenite grain size of about 150 nm was achieved for the 201L steel containing 0.08 wt.% N after reversion annealing at 800 °C for 60 s. The mechanical properties of the reversion-annealed N-bearing steels were enhanced due to both N alloying and grain refinement.
KeywordsAISI 201L stainless steel martensite thermomechanical process nano/ultrafine grain structure nitrogen
The authors would like to express their thanks to Dr. P. Behjati and Mr. Fadavi for their valuable supports in experimental works.
- 1.H.K.D.H. Bhadeshia and R. Honeycombe, Steels Microstructure and Properties, 3rd ed., Elsevier Science, Oxford, 2006Google Scholar
- 2.M.F. McGuire, Stainless Steels for Design Engineers, ASM International, Metals Park, OH, 2008Google Scholar
- 4.J.C. Lippold and D.J. Koteck, Welding Metallurgy and Weldability of Stainless Steels, Wiley, New Jersey, NJ, 2005Google Scholar
- 6.E. Werner, P.J. Uggowitzer, and M.O. Speidel, Mechanical Properties and Aging Behavior of Nitrogen Alloyed Austenitic Steels, Proc. Fifth Int. Conf. on the Mechanical Behavior of Materials, Beijing, 1987, Vol. 1, p. 419Google Scholar
- 15.H.L. Bing, J.Z. Hua, Z.Z. Rui, and Y. Yan, Effect of Grain Size on Mechanical Properties of Nickel-Free High Nitrogen Austenitic Stainless Steel, J. Iron. Steel Res. Int., 2009, 16, p 58–61Google Scholar
- 20.K. Lücke and H.P. Stüwe, Recovery and Recrystallization of Metals, Interscience, New York, 1963Google Scholar
- 21.F.J. Humphreys and M. Hatherly, Recrystallization and Related Annealing Phenomena, 2nd ed., Pergamon, Oxford, 2004Google Scholar