Abstract
Currently, application of multiphase steels for automotive products is one of the prospects for the development of this area of industry. The peculiarity of the microstructure that determines the properties of the final metal products from multiphase steels is its formation or change under affect of external thermal deformation. The article describes the possibility of using the basic principles of the theory of Joint plastic deformation of dissimilar bodies in relation to the processes of thermal and deformation treatment of multiphase steels. A distinctive feature of the proposed approach is the consideration of the type and quantitative ratio of phases that steel structure consists of. To take into account the share of a particular phase in the total volume of material, it is proposed to use the concept of “phase filling factor”. The developed approach is based on the fact that multiphase steels can be represented as a multicomponent structure consisting of soft and hard components, which are the forming phases. Moreover, every phase has its own characteristic properties, which determine its ability to undergo plastic deformation. Analytical equations have been obtained which make it possible to take into consideration both the change in the number of phases during the process of thermal and deformation treatment of multiphase steel and their properties. The developed approach can be used to design technological processes for the manufacturing the metal products from multiphase steels using various methods of plastic deformation.
Keywords:
theory of Joint plastic deformation of dissimilar bodies, multiphase steel, microstructure, phase composition, properties, thermal and deformation treatment