Detection of Decarburising Depth in Hadfield Steels Using a Multi-magnetic NDE Method

This paper reports the capability of a range electromagnetic non-destructive evaluation (NDE) methods to characterise decarburising phenomena in Hadfield steels. Four steel samples were austenitised at 1050 °C for 1, 2, 3 and, 4 hours an air furnace followed by water quenching produce various depths. The decarburisation depth was characterised using hardness profile measurements, optical and scanning electron microscopy, X-ray diffraction analysis. results confirmed occurrence presence surface martensite layer 35 110 µm depending on austenitisation time. microstructural change affects magnetic properties sample enables NDE detect transformed layers quantitatively. In characterisation step, relationships between austenitising time outputs from flux leakage (MFL), initial magnetisation curve (BH) eddy current (EC) are reported. Comparing obtained three methods, it can be concluded that MFL EC (phase angle output) have potential quantify changes occurring as result process