The Use of Eddy Current Nondestructive Test for the Quality Control of arburized Components

Carburization is a common way to improve the performance of low carbon steel components used in industries. Accurate control of surface carbon content of carburized steels is the most important factor for the obtainment of desirable properties. A variety of methods exists for determination of surface carbon content, however, all of them are expensive and time consuming, and accordingly, all the samples cannot be tested. In this research, the capability of Eddy Current nondestructive method for determination of surface carbon content of steel components was evaluated. The Eddy Current tests were performed in order to determine the relationship between the surface carbon content and the normalized impedance, the input and output voltages. The results showed an appropriate relationship (with R2=0.82) between the surface carbon content and the normalized impedance. Moreover, the effect of test temperature on the mentioned relationship was also investigated. The relationship obtained in this way was suitable for the determination of the surface carbon content of the steel in a more accurate fashion.