Physically Based Model for Static and Dynamic Behaviour of TRIP Steel
Low alloy multiphase TRansformation Induced Plasticity (TRIP) steels offer an excellent combination of a large uniform elongation and a high strength. This results from the composite behaviour of the different phases that are present in these steels: polygonal ferrite, bainitic ferrite and a martensite/austenite constituent. In order to obtain a clear understanding of the behaviour of the different constituents within the multiphase steel, they were prepared separately. The stress-strain relationship of the different single phase and multiphase steels were simulated with physically based micromechanical models. The model used to describe the stress-strain curves of the separate phases is based on the Mecking-Kocks and Seeger-Kocks theories and uses physical properties such as the microstructural properties and the chemical composition of the different phases. Strain-induced transformation kinetics, based on a generalized form of the Olson-Cohen law, were used to include the influence of the transformation of the metastable austenite. Static stress-strain properties of multiphase steels were modelled by the successive application of a Gladman type mixture law for two-phase steels. The model yields detailed information of stress and strain partitioning between the different phases during a static tensile test. A model for the dynamic stress-strain properties of ferritic steels is also proposed.
T. Chandra, K. Tsuzaki, M. Militzer and C. Ravindran
J. Bouquerel et al., "Physically Based Model for Static and Dynamic Behaviour of TRIP Steel", Advanced Materials Research, Vols. 15-17, pp. 744-749, 2007