Moat, R. J.; Zhang, S. Y.; Kelleher, J.; Mark, A. F.; Mori, T. and Withers, P. J.
|DOI (Digital Object Identifier) Link:||http://doi.org/10.1016/j.actamat.2012.08.011|
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Transformation-induced plasticity (TRIP) steels are becoming increasingly exploited for industrial applications because they show high strength and high uniform elongation (ductility). Despite this interest, the relative contributions of the various strengthening and straining mechanisms are often poorly understood. In this study, neutron diffraction is employed to quantify the contribution of different mechanisms to ductility and work hardening for a 0.25 wt.% C steel. Differences in stress–strain response at different temperatures are related to the extent of the transformation of metastable austenite into martensite during deformation. At room temperature (RT) the transformation of austenite occurs gradually with straining, while at −50 °C the transformation occurs almost from the onset of loading. The associated transformation strain is reduced, comprising nearly half the total strain, lowering the apparent elastic modulus and explaining the relatively low work hardening compared to RT straining. By contrast, deformation at RT after pre-straining at −50 °C results in larger work hardening than for solely RT straining due to the higher martensite levels introduced at −50 °C. This is due to composite load transfer to the strong constituent from the soft matrix. The extent of the transformation is quantified as a function of strain at both temperatures as well as its effect on the work hardening and elongation.
|Item Type:||Journal Article|
|Copyright Holders:||2012 Acta Materialia Inc.|
|Keywords:||TRIP; martensite; neutron diffraction; steel|
|Academic Unit/Department:||Faculty of Science, Technology, Engineering and Mathematics (STEM) > Engineering and Innovation
Faculty of Science, Technology, Engineering and Mathematics (STEM)
|Depositing User:||Richard Moat|
|Date Deposited:||11 Oct 2012 08:24|
|Last Modified:||02 Aug 2016 14:20|
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