Abstract There are two different approaches to model the kinetics of the bainite transformation. The diffusional growth model needs to adopt the solute drag effect, and a quantitative approach is proposed although the diffusion of substitutional alloying elements is not fully accepted experimentally. The nucleation-controlled model based on the displacive and diffusionless nature of the bainite transformation, combined with the kinetics of cementite formation in austenite and in ferrite as the simultaneous reactions.