The bainitic and the martensitic load-dependent phase transformations of low alloy 51CrV4 steel were investigated. Both, the austenitization treatments and the loads were derived from an thermo-mechanically coupled forging process investigated within the Collaborative Research Center Transregio 30. In addition, the monotonic and cyclic deformation behaviors of the resulting microstructures were determined. The datanot only allowed for a more accurate prediction of the final microstructures, but also offered the opportunity to determine optimized microstructure distributions in the final work pieces for several different applications.It was found that both, the superimposition of stresses throughout the transformation and pre-straining of the supercooled austenite wereeffective in accelerating the bainitic phase transformation kinetics. Due to the additional nucleation sites introduced during pre-straining an even more pronounced acceleration effect was observed in this case. However, when the transformation proceeded under internal or external stressestransformation plasticity strains had to be considered, since they affect the dimensional stability. Additional EBSD studies revealed that the evolution of transformation plasticity strains could be attributed to variant selection. However, when tensile (compressive) pre-deformationsand compressive (tensile) stresses superimposed throughout the transformation were combined in an optimized manner, transformation plasticity strains are avoidable, whereas the overall transformation kinetics are still accelerated as compared to a transformation proceeding without any superimposed stresses.