Refinement of the Structure of Microalloyed Steels Under Plastic Deformation Near the Temperatures of Polymorphic Transformation

The effects of plastic deformation near the temperatures of the F -> A phase transformation and of deformation-induced ferritic transformation (DIFT) on the structure and properties of microalloyed ferritic-pearlitic steels are studied. It is shown that the refinement of the structure of the steels due to the F -> Atransformation during heating and due to the DIFT under plastic deformation and subsequent cooling raises the mechanical properties of the metal. Modes of hot rolling are suggested for structural ferritic-pearlitic steel 17G1S-U in order to form an ultrafine-grained structure with elevated mechanical properties.