Preliminary study of residual stress measurement using eddy currents phasor angle

Abstract

Residual stress detection and evaluation has been of crucial importance, and also problematic for many years. There are many methods of residual stresses determination based on destructive and non-destructive way of approach. Nowadays there are still undiscovered possibilities to determine these internal stresses. Opportunity to detect residual stress on line directly, without using big and expensive devices is motivation for presented work. Presented article is focused on possibility to determine the residual stresses induced in conductive materials using eddy currents phasor angle. Using eddy currents method gives opportunity for quick on line measurement of residual stresses. Induced stress causes in base material slight deviation in permeability and conductivity, which can be detected using standard eddy currents flaw detector. Experimental procedure included annealing for stress relief, manufacturing by face milling and measurement of residual stresses using x-ray diffraction and eddy currents. Results of experimental research lead to extension of knowledge in the field of residual stresses. Presented method is applicable for assessment of residual stresses in many components.