Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1580391 | Materials Science and Engineering: A | 2009 | 8 Pages |
Abstract
The complex character of plastic deformation of the austenitic steel Fe22Mn0.6C is studied at room temperature with the aid of high-frequency local extensometry. It is shown that the plastic flow instability, associated with fluctuations of the flow stress, results from quasi-continuous propagation of deformation bands along the specimen axis. This propagation mode is dominant in the entire range of the applied strain-rate from 2.1Â ÃÂ 10â5Â sâ1 to 10â1Â sâ1. Such behavior differs from that of various alloys deforming via dislocation glide under conditions of dynamic strain ageing (Portevin-Le Chatelier effect), which is characterized by a transition from a repetitive occurrence of static deformation bands at lower strain rates to a relay-race and, finally, quasi-continuous deformation band propagation at higher strain rates. The unusual behavior of the deformation bands bears evidence to a particular kind of instability in the investigated steel. A possible role of deformation twins in the observed dynamics of plastic instability is discussed.
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Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
T.A. Lebedkina, M.A. Lebyodkin, J.-Ph. Chateau, A. Jacques, S. Allain,