Quantitative investigation of a standard test shim for magnetic particle testing

Quantitative investigation of a standard test shim for magnetic particle testing has been carried out. The current values of the magnetizing yoke to obtain magnetic particle indication were measured experimentally. An analytical model for the experimental conditions was then formulated to obtain the amplitude of the leakage magnetic flux from an artificial groove in a type A standard test shim. The magnetic flux densities in the type A standard test shim and the test object were obtained using finite element analysis.In a test object with high permeability, the magnetic flux density was almost in the saturation regime when the magnetic particle indication was obtained. On the other hand, in a test object not having high permeability, the magnetic flux density was small when magnetic particle indication was obtained.

Graphical AbstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The magnetic flux density in a type A standard test shim and a test object was obtained experimentally and using FEA. ► The flow of the magnetic flux in the type A standard test shim and the test object was clarified for the measurement mechanism of the magnetization intensity of the test object. ► The magnetic flux density was almost saturated for the test object having good magnetic properties, when the magnetic particle indication from the artificial groove of the standard test shim was obtained. ► The magnetic flux density of the test object was small when the magnetic particle indication from the artificial groove of the standard test shim was obtained for the test object not having good magnetic properties.