Evaluation of mechanical properties in medium carbon steel with a point mode electromagnetic sensor

This paper reports the evaluation of mechanical properties of medium carbon steel based on a novel sensor. The novel point mode electromagnetic sensor with compact configuration and concentrated magnetic flux characteristics has attracted wide attention in recent years. The point mode electromagnetic sensor consists of exciting coil, receiving coil and needle permalloy core embedded into the coil. Response surface methodology was adopted to explore the relationships between the structure paramerters of core (contact radius and height of the cone) and magnetic field intensity based on finite element analysis. The analysis results showed that the contact radius and cone height of the core had important influences on magnetic field intensity. The influence of the cone height was lesser than that of the contact radius. Moreover, the mathematic model was verified effectively by testing magnetic field intensity of different cores based on scanning techniques. Mechanical properties experiment results measured by using a novel sensor showed that a linear correlation exists between the values of amplitude for fundamental and the hardness of samples.