Identification of the micro-plasticity mechanisms at the origin of self-heating under cyclic loading with low stress amplitude

The aim of the present work is to study the mechanisms at the origin of the two self-heating regimes under cyclic loading observed for stress amplitudes lower than the conventional yield stress. To achieve this objective, several different and complementary microscopic observation techniques have been performed: optical microscopy, Scanning Electron Microscopy (SEM) and Atomic Force Microscopy observations and Electron BackScatter Diffraction (EBSD) measurements have been carried out on the surface of several specimens after cyclic loading. All the results presented hereafter have been obtained on an HSLA (i.e., High Strength Low Alloy) commercial steel.