Evaluation of the Growth of Dislocations Density in Fatigue Loading Process via Electrical Resistivity Measurements

The paper focuses on quantitative evaluation of the microstructural changes - growth of the dislocation density - in stainless steel specimens subjected to fatigue loading. We propose to use electrical resistivity measurements for this goal. Change in electrical resistance of the specimens has been monitored in dependence on the number of fatigue cycles and the relative growth of the dislocation density was calculated from these data and known values of the specific resistivity of dislocations for iron. We also estimated the growth of dislocation density using analysis of Scanning Electron Microscopy (SEM) images of etched specimens. This estimate however appears to be unreasonably low, so that SEM may be used for qualitative analysis only.