The Retained Austenite Measurement Technology by Nine-feet Sensor

Based on the saturation magnetization, the relation of the retained content of austenite and ac magnetic permeability is deduced. Optimized by finite element method, the structure of nine feet probe is used to detect some Q235 samples with different austenite content. The results are in good agreement with the samples calibration, and it tells that this method is suitable to detect the content of residual austenite.