Evaluation of fatigue damage using a magnetic measurement technique

A series of strain-controlled fatigue tests were performed on 0.1 wt% C Fe- C alloy samples under different strain amplitudes. The measured coercivity of these samples was found to behave differently in the initial and final s tages of fatigue. In the intermediate stage of fatigue it was found that co ercivity tended to increase, while initial and maximum permeabilities tende d to decrease. This could be related to the changes in the surface structur e which were observed by SEM, The present results indicate that hysteresis parameters are related to the accumulation of fatigue damage, and therefore it is possible to develop a magnetic measurement technique for monitoring fatigue damage in steel. components.