Study of Phase Transformation of Medium Carbon Steel after Hot Plastic Deformation

The CCT and DCCT diagrams of steel C60 (with approx. 0.6 % C) were constructed on the basis of dilatation tests with and/or without an influence of the previous deformation and they were then compared, order to make an evaluation of the influence of the previous deformation on the phase transformation kinetics. For the execution of the experiment, the dilatation module of the plastometer Gleeble 3800 was used. The accuracy of the diagrams was faced with metallographic analyses and measurements. The previous deformation expressly retarded a bainite transformation and slightly accelerated ferrite and pearlite transformations. The martensite start temperature was practically not influenced by the previous deformation; however, the applied deformation caused the creation of the martensite at lower cooling rates.