Solid State Phase Transformations in Medium Manganese Steels

Steels are still, and probably will remain in future, the primary choice for applications as structural materials. This is not only because of the reasonable ratios of properties over production costs, but also owing to the versatile properties realisable via variety of microstructures achieved by controlling the solid-state phase transformations between austenite and ferrite phases in steels. The noticeable improvements in the properties of advanced high strength steels since the invention, have led to development of three generation of these steels. A sustainable continuous improvement in developing new grades of steels, requires more and deeper understanding of the effect of macroscopically controllable parameters, such as overall composition and temperature variations, on the rate of nucleation and migration of interfaces during solid-state phase transformations. In this PhD thesis, experimental and modelling approaches are developed and employed to study the effect of alloying elements, such as Mn and C, on migration behavior of interfaces during solid state phase transformations at high and low temperatures...