Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
778375 | International Journal of Fatigue | 2012 | 6 Pages |
Fatigue failure of steel occurs when cracks form in a component and continue to grow to a size large enough to cause failure. In order to understand the strength of a steel component it is important to locate these cracks. We developed a scanning Hall probe microscope (SHPM) equipped with a GaAs film sensor and observed fatigue cracks at room temperature in air while they were growing. In this paper we report two important findings regarding the magnetic field properties: a decrease in the magnetic flux density at the early fatigue stage and the polarization of the magnetic field ahead of the fatigue cracks occurring during crack growth.
► We developed a scanning Hall probe microscope (SHPM) equipped with a GaAs film sensor. ► We succeeded to observe fatigue cracks at room temperature in air while they were growing. ► One of the important findings regarding the magnetic fields is that the magnetic flux density decreases during crack growth. ► The other is that polarization of the magnetic field occurs ahead of the fatigue cracks.