Spoluautoři PETRYSHYNETS Ivan, SOPKO Martin, KOVÁČ František

An investigation of the dependence of grains hardness on their orientation in electrical steel is presented in the present work. The study was performed by means of nanoindentation experiments using Nanoindenter G200 with the calibrated Berkovich indenter. Nanoindentation measurements were made at room (26 °C) and at elevated temperatures (100 °C, 200 °C, 250 °C). Nanohardness measurements were carried out in non-oriented silicon steel with columnar microstructure, in order to evaluate local variation of work hardening as a function of crystallographic orientation. The grain orientations with respect of individual rolling planes and rolling orientation was determined by EBSD (electron back scattered diffraction) analyses. An EBSD analysis was used also to determine grain orientations, in which were made the nanohardness measurements. Indentation hardness HIT was determined from load-displacement curves within individual grains (G1, G2, G3) with various crystallographic orientations. Hardness was shown to decrease with increasing temperature in each of individual grains. The differences of hardness values were observed also between particular grain orientations. It is shown that for a specific deformation, the behavior of each grain is determined only by its current orientation and slip system.