Eddy-current testing of mechanical characteristics of pressure vessel metals at high frequencies

Abstract

The dependence of the changes in specific electric conductivity on mechanical stresses in nonmagnetic metals was investigated by the eddy-current method. For this purpose, we used an eddy-current transducer with a frequency of 400 MHz, which allows one to perform local tests of the surface layers of materials. We established that the specific electric conductivity of nonmagnetic metals of pressure vessels linearly depends on equivalent stresses. We also suggest an approach to the prediction of limiting states of pressure vessels on the basis of the results of eddy-current tests.