Potential drop application to determine the electrical conductivity of a deformed steel sample

This work is devoted to the study of the using the potential drop method possibility to identify local stress concentration zones and assess the metal deformation degree in these zones. Paper presents the finite element modeling results of the current circuits propagation in objects with locally deformed regions that occur in places of increased mechanical stresses concentrations. To identify areas with varying degrees of deformation, a method for recording the specific electrical conductivity increment is proposed (Δρ/ρ0) according to the voltages values δU detected as application result of the potential drop non-destructive method using a sinusoidal current source. The current circuits excitation at frequencies f less than 10000 Hz allowed us to determine the most informative approximating function δU(f) parameters, allowing to synthesize a model of multiple linear regression correlating with the parameter Δρ/ρ0 values, and with the degree of product material deformation.