Monitoring of corrosion extent in steel S460MC by the use of magnetic Barkhausen noise emission

Abstract

Monitoring of corrosion extent is critical in bridge operation and civil buildings. Reducing the effective cross-sectional area of components can redistribute the stress state and increase the true stress in the critical parts of civil structures. Unexpected rupture of bodies can occur as a result of their over-stressing. However, it is not possible to take relevant samples from these structures for a laboratory analysis during their lifetime. For this reason, this study investigates the potential of magnetic Barkhausen noise analysis for real-time corrosion extent monitoring. This study demonstrates that Barkhausen noise emission drops down along with an increasing degree of corrosion of steel S460MC. Progressive and remarkable decrease of Barkhausen noise and alteration of extracted features result from increasing surface roughness and superimposing influence of the increasing thickness of the near-surface layers containing mainly iron oxides. Furthermore, it was found that corrosion on the surface also alters the relation between tensile stress and Barkhausen noise within the interaction volume. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.