ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Two-stage sequences of simple shear and/or uniaxial tensile tests conducted on TRIP800 steel sheet and supplemented by texture measurements are reported. The purpose is a better understanding of the macroscopic work-hardening behaviour and its microstructural origin. According to the previously published work on single phase ferrite steel; the peculiar macroscopic transient effect in flow stress wasmainly associated to the microstructural destabilization (e.g. reinforcement, dissolution or rearrangement of the previously formed dislocation walls). In addition, the macroscopic work-softening observed at the beginning of the second stage of cross-loading was attributed to the micro-band occurrence. Considering the actual multiphase steel, the main difference lies in the absence of the peculiar transient effect in flow stress upon cross-loading (where no macroscopic work-softening is observed) and the associated microstructural mechanisms (no formation of micro-bands). Besides, the initial texture for the actual multiphase steel is in some extent different to the previously investigated single phase steel mainly made up of the γ-fibre. Therefore, a detailed analysis of the measured deformed textures is carried out in order to investigate the contribution of the texture evolution on the macroscopic work-hardening. The computations of the orientation stability map as well as the predicted texture evolutions using the classical full constraint Taylor-Bishop-Hill (TBH) model are performed for a better understanding of the observed texture development. The influence of the texture evolution on the shape of the stress-strain curves, as well as on the remaining symmetries of the material, is also discussed. Explicitly, we show that despite the presence of a well developed texture in the as-received and deformed material, the contribution of the geometrical hardening (i.e. textural evolution) on the macroscopic behaviour remains small compared to the microstructural one
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/11/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.495-497.1097.pdf
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