Microstructure Evolution in a 304-Type Austenitic Stainless Steel during Multidirectional Forging at Ambient Temperature

Abstract:

The formation of nanocrystalline structure in a 304-type austenitic stainless steel during multidirectional forging (MDF) at room temperature was investigated. Initial coarse austenite grains with an average size of 50 μm were refined to about 80 nm by martensitic transformation during MDF to a total true strain of 2 and remained unchanged upon further deformation up to a strain of 4. The volume fraction of martensite achieved ~0.9 after forging to a strain of 1.6. The MDF at room temperature was accompanied by a significant hardening of the 304-type steel. The microhardness and the flow stress increased during forging and approached their saturations on the levels of about 5 GPa and 1.7 GPa, respectively, after total true strain of 2. The structural mechanisms responsible for microstructure evolution during severe deformation are discussed.

• Periodical: Materials Science Forum (Volumes 783-786)
• Pages: 831-836
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.783-786.831
• Online since: May 2014
• Authors: Alla Kipelova*, Marina Odnobokova, Andrey Belyakov, Rustam Kaibyshev
• Keywords: Austenitic Stainless Steel, Grain Refinement, Martensitic Transformation (MT), Microstructure Evolution, Multidirectional Forging

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