The Application of Magnetic, Electromagnetic-Acoustic and Eddy-Current Methods to the Assessment of Plastic Deformation under Cyclic Loading of Annealed Medium-Carbon Steel

摘要

The influence of fatigue stressing of annealed medium-carbon steel (with 0.45 wt. % of carbon) on the change of magnetic, electromagnetic-acoustic and eddy-current characteristics of the steel has been investigated. It has been shown that the coercive force, residual magnetic induction and the velocity of acoustic wave are sensitive to both large and small plastic deformations and that the readings of the eddy-current instrument are highly sensitive to small and mediate deformations accumulated under fatigue loading. The residual mechanical properties of the steel after cyclic loading have been established, as well as a correlation between these properties and the magnetic and eddy-current characteristics. The feasibility of magnetic, electromagnetic-acoustic and eddy-current nondestructive testing of accumulated plastic deformation and estimating of residual material life under cyclic loading has been demonstrated.