Evaluation of rail decarburisation depth using a H-shaped electromagnetic sensor

This paper reports the evaluation of rail decarburisation based on eddy current methods using an H-shaped sensor. Rails with different levels of decarburisation, due to different bloom reheat times (195 min–613 min), were used. Experimental results have indicated that the measured inductance of the sensor is closely related to the reheat furnace dwell time of the rail samples. Quantification of the amount of decarburisation, using micro-hardness tests and visual evaluation, and the predicted amount (based on Fick's law), have been compared with the eddy current approach, with reasonable agreement being seen.