Analysis of Structure Transformations in Rail Surface Induced by Plastic Deformation via Barkhausen Noise Emission

This paper reports about magnetic Barkhausen noise emission of the rail surface exposed to long time cyclic plastic deformation. Severe plastic deformation of the rail surface induces remarkable structure transformations and alterations of stress state which contribute to valuable decrease of the Barkhausen noise emission compared to untouched surface of the rail. The paper analyses correlation between the Barkhausen noise signals (as well as extracted Barkhausen noise envelopes) and surface state (expressed in terms of micrographs, microhardness readings and residual stresses). This study would contribute to a possible concept for preventing unexpected rails deformation (or cracking) due to their thermal dilatation via the Barkhausen noise technique.