Monitoring of S235 steel over-stressing by the use of Barkhausen noise technique

•Low Barkhausen noise alerts incoming S235 steel rupture.•Evolution of MBN is a function of true stress and microhardness.•Easy axis of magnetization shifts along with plastic straining. This paper deals with monitoring of the rupture of S235 steel used in ship structures under uniaxial loading by the use of a non-destructive magnetic method based on Barkhausen noise emission. Component failure in constructions of marine or civil engineering can be found during their long-term operation or/and over-stressing. Especially the corrosion process can significantly reduce effective cross-section area of structures, which in turn increases true stresses. This study demonstrates that Barkhausen noise emission and extracted parameters can reliably reveal structure over-stressing. A remarkable decrease of Barkhausen noise near the true yield stress alerts the high risk of incoming breakage. It was found that the evolution of Barkhausen noise is driven by the steel hardening (expressed in terms of hardness and the corresponding dislocation density) and the superimposing stress state.