VALIDATION OF THERMOMECHANICAL AND MICROSTRUCTURAL MODELS FOR NIOBIUMSTEELS IN HOT ROLLING-DRAWING

The paper deals with the problem of validation of microstructure evolu tion models for the niobium steels. Two models, developed by Dutta & S ellars and by Hodgson, and describing processes of recrystallization c ontrolled by the precipitation of carbonitrides, are considered. These models are implemented into the finite element program for the hot dr awing of strips, what allows the investigation of the microstructure d istribution through the thickness of the strip. The process of mull-pa ss hot drawing of niobium steel flat samples through the set of roller dies is used to validate the predictions of the models.