Transformation diagrams of selected steel grades with consideration of deformation effect

Abstract

The aim of this article was to assess the effect of previous plastic deformation on the transformation kinetics of selected steels with a wide range of chemical composition. Transformation (CCT and DCCT) diagrams were constructed on the basis of dilatometric tests on the plastometer Gleeble 3800 and metallographic analyses supplemented by measurements of HV hardness. Effect of previous deformation on transformation was evaluated of the critical rate of formation of the individual structural components (ferrite, pearlite and bainite) in the case of formation of martensite respect to M-s temperature. Previous plastic deformation accelerated especially diffuse transformations (ferrite and pearlite), temperature of M-s was lower after previous plastic deformation and bainitic transformation was highly dependent on the chemical composition of steel.