Materials Science and Engineering

Biography

Biography: Remigiusz BÅ‚oniarz

Abstract

Micro alloyed HSLA steel was subjected to advanced thermo mechanical processing. The unique combination of processing parameters and microstructural phenomena i.e., combined metal forming consisted of cold rolling and subsequent thermo mechanical rolling, recrystallization and precipitation processes during reheating allow to study the role of prior austenite morphology in the development process of ultrafine grained and bimodal microstructures. Produced in the thermo mechanical processing material was analyzed and characterized using optical metallography, Electron Back Scattered Diffraction (EBSD), Scanning Electron Microscopy (SEM), and X-ray Diffraction (XRD). The results show a clear effect of the paths of thermo mechanical treatment on microstructure development and mechanical response of produced in such a way micro-alloyed steel specimens. The investigated specimens were subjected to the compression and tension tests under quasi-static and dynamic loading conditions. In these tests a wide range of strain rate was applied to demonstrate the ability of the investigated inhomogeneous microstructures to accommodate the deformation effects under dynamic loading conditions. It has been shown that produced in the thermo mechanically processed specimens complex microstructures effectively inhibit nucleation of the stress concentrations. It was observed that the deformation energy dissipates on the interphase boundaries due to the differences in mechanical response of the microstructure components.