Influence of Hot-Working Conditions on a Structure of X11MnSiAl17-1-3 Steel

Abstract

The investigations are focused on high-manganese austenitic steels used for reinforcing elements of car body. The purpose of this work was to examine the influence of thermo-mechanical treatment workout using Gleeble simulator and LPS module for semi-industrial hot-rolling on the structure and transformations occurring during cold deformations. Thermo-mechanical treatment consists of four passovers with a planned strain rate of about 20%. There were three variants of cooling after thermo-mechanical treatment: cooling in water, natural air-cooling and cooling in water after isothermal holding in the temperature of last deformation 850°C for 30 s. Structural observation were carried on LEICA MEF4A light microscope, analysis of the chemical composition were made with XPert PRO diffractometer, and the results were analyzed with OriginLab. It was found that the high-manganese austenitic X11MnSiAl7-1-3 steel after thermo-mechanical treatment on Gleeble simulator is characterized by dynamically recrystallized structure. In intervals time between each compression metadynamic and static recrystallization take place. After hot-rolling these steels has austenitic structure with dynamically recovered grains and with small metadynamically and statically recrystallized grains that are located on a border of elongated grains of austenite.