The depth of scientific understanding of martensitic transformations provides a strong foundation for the predictive design of materials exploiting artensitic phenomena. Recent theoretical advances supporting this capability include twoand three-dimensional applications of Landau–Ginzburg heory to martensitic nucleation, and important refinements of multiscale kinetic theory. Accurate control o...

We show that in metamagnetic shape memory alloys exhibiting a magnetostructural first order phase transition the direct transition from ferromagnetic austenite to nonmagnetic martensite is isothermal. In contrast to the direct transformation, the reverse one nonmagnetic martensite–ferromagnetic austenite is athermal, just as are athermal both direct and reverse martensitic transformations in co...

Low-temperature plastic flow in TRIP steels has been found to be controlled by stress-assisted isothermal martensitic transformation. For these conditions, the thermodynamics and kinetic theory of martensitic transformations leads directly to constitutive relations predicting the dependence of flow stress on temperature, strain, strain-rate, and stress-state, consistent with the observed behavi...

There are two well-known phenomena associated with the bainite reaction, both of which have been exploited here to enhance the mechanical behaviour of steel. Firstly, the bainite plate size decreases as the transformation temperature is reduced. Secondly, it is bad to have large regions of untransformed austenite in the microstructure; this is because they can transform, under the influence of ...

The effects of boron segregation and austenite grain size on the bainitic isothermal transformation a high-strength steel were studied independently. Dilatometry, microstructural observations previous atom probe tomography analyses showed that rate decreases with increasing excess at boundaries. We also found causes an unexpected effect: large grains transform faster than small ones. A kinetic ...