<p>To classify the strengthening mechanisms of Ti-microalloyed steels under ultrafast cooling strategy, three steels with different Ti–Mn contents were prepared to study the mechanical properties dependence of microstructure. It is verified that the yield strength increases significantly at lower content range of Ti content. Metallographic microscopy (OM), scanning electron microscopy (SEM), orientation distribution function (ODF) and transmission electron microscopy (TEM) are employed to characterize the grain size, precipitates, pearlite morphology and texture components. It is found that grain size decreases significantly with increasing Ti content, and pearlite exhibits uneven lamellae in low-Ti steels, while fine non-equilibrium eutectoid contains Fe₃C and FeC precipitates with certain orientation relationship. It is revealed that grain refinement and dislocation strengthening are the main two strengthening mechanisms for the prepared Ti-bearing steels. Increasing Ti content elevates the critical precipitation temperature of TiC precipitation during rolling process, and results in the strengthening effect under rapid cooling condition.</p>