Examination of ferromagnetic materials using Magnetic Recording Method

Abstract

This paper shows an experimental investigation of the steel-made samples using a novel nondestructive testing technique, the Magnetic Recording Method (MRM). The technique is intended to examine stress or fatigue-loaded ferromagnetic structures. First, the material has to be magnetized (e.g. using an array of permanent magnets) to obtain a specific magnetization path with a quasi-sinusoidal shape. Then, remanence is measured and recorded for further analysis. After the operation or static stress load, the measurement is repeated. Analysis of the relative change in magnetization enables applied stress to be identified unequivocally.