Research on Powder Metallurgy High Nitrogen Stainless Steels

Abstract:

High nitrogen Fe-18Cr-12Mn-3Mo-xN austenitic stainless steels were prepared by mechanical alloying and powder metallurgical pressing-sintering techniques. The microstructures, nitrogen contents and sintering properties of the milled powders and sintered bodies had been also investigated. The results show that high nitrogen and nearly spherical composite powders with good compressibility can be obtained by high-energy vibration ball milling and high temperature nitriding. It is also found that the sintering temperature has a significant effect on the density and the nitrogen content of sintered specimens, and the optimal sintering temperature are determined to be 1250°C, at which a favorable combination of the relative density as high as 97.1% and the final nitrogen content of 0.79wt% in sintered specimens can be obtained. The sintered bodies mainly consist of γ-austenite, α-ferrite and the lamellar Cr₂N phase. After solution-annealing at 1150°C for 1.5h followed by water-quenching, high nitrogen austenitic stainless steels reveal a fully austenitic structure.

• Periodical: Advanced Materials Research (Volumes 690-693)
• Pages: 172-175
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.690-693.172
• Online since: May 2013
• Authors: Da Wei Cui, Jin Long Wang
• Keywords: Austenitic Stainless Steel, High Nitrogen, Mechanical Alloying, Powder metallurgy

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