Sensitization is precipitation of chromium carbide in stainless steels during exposure to high temperatures service that leads to premature corrosion failure of components. It is well known that during sensitization process, chromium carbide forms at the grain boundary along with chromium depletion near the grain boundary resulting in the change of the magnetic property of the steel from paramagnetic to ferromagnetic. From this study, it is clear that the magnetic characterisation is sensitive enough to detect the sensitisation. However, the magnetic behavior has contributions from both ferromagnetic and super paramagnetic nature of the phase.