Numerical and experimental study on thermo-mechanical processing of medium-carbon steels at low temperatures for achieving ultrafine-structured bainite

A combination of experimental and numerical approaches was applied for constructing a dynamic model thermomechanical processing, which used simulating laboratory rolling cooling, designing cooling path to enable phase transformation from austenite ultrafine ( ∼ 50–100 nm) bainitic laths. Physical simulation experiments were calibrating the models. Hot water conducted they numerically simulated. The calibrated models main processing stages affecting final microstructure evolution during scale i.e. low temperature (500 °C) ausforming subsequent schedules leading decomposition into bainite martensite. fitted parameters results are presented two different paths: (i) air 350 °C with holding 1–1.5 h, (ii) close martensite start temperature, furnace h. Microstructural analysis carried out using scanning electron microscopy combined backscatter diffraction as well X-ray structures corroborated mechanical properties evaluated in respect hardness, tensile impact toughness properties. achieved microstructures further interpreted results. show that simulations provide an effective tool suitable paths desired microstructure.