The processing-microstructure-property relationships in steels continue to present challenges to researchers due to the complexity of phase transformation reactions and the wide spectrum of microstructures and properties achievable. This major two-volume work summarizes the current state of research on phase transformations in steels and its implications for the emergence of new steels with enhanced engineering properties. Volume 2 reviews current research on diffusionless transformations and phase transformations in high strength steels, as well as advances in modeling and analytical techniques which underpin this research. Chapters in part one discuss the crystallography and kinetics of martensite transformations, the morphology, substructure and tempering of martensite as well as shape memory in ferrous alloys. Part two reviews research on phase transformations in high strength low alloy (HSLA) steels, transformation induced plasticity (TRIP)-assisted multiphase steels, quenched and partitioned steels, advanced nanostructured bainitic steels, high manganese twinning induced plasticity (TWIP) and maraging steels. The concluding two parts review advances in modeling and the use of advanced analytical techniques to improve the understanding of phase transformations in steels.