Investigation of Barkhausen Noise Emission in Steel Wires Subjected to Different Surface Treatments

Abstract

Steel rope wires represent the main bearing components of bridges whose long-term operation depends on loading conditions, corrosion attack, and/or pre-stressing. Corrosion attack especially can remarkably reduce the effective cross-sectional area, which in turn over-stresses the wires and redistributes stress to the neighboring wires. The premature collapse of many bridges is very often caused by wire rupture as a result of their poor corrosion protection. For these reasons, various processes—such as galvanizing, phosphating, etc.—have been applied to steel wires to increase their resistance against corrosion. However, these processes can alter the microstructure, especially in the near-surface regions. The Barkhausen noise technique has been already reported as a suitable technique for investigating corrosion extent and true pre-stress in the steel rope wires. This study reports that non-homogeneity of the surface state of wires undergoing different surface treatment makes it more difficult to assess the true stress state and increase the uncertainty of Barkhausen noise measurement. Barkhausen noise signals are correlated with metallographic and SEM observations as well as microhardness measurements. The non-homogeneity of the surface state of wires is also investigated by the use of chemical mapping and linear chemical analyses.

Attenuation of Barkhausen Noise Emission due to Variable Coating Thickness

“…Furthermore, rupture of certain components in the structure can redistribute the stress to the neighboring regions and accelerate its collapse [12,13]. In order to improve the corrosion resistance of bridges made of steels, their surface is coated by protective multilayers of variable thickness and composition [14,15]. Due to the quite large dimensions of bridges and the corresponding steel components (being welded together), deposition of these layers is carried out by hand using spraying systems or brushes.…”

Magnetic Measurement of Zn Layer Heterogeneity on the Flange of the Steel Road Barrier

“…The nitriding process produces the thin nitriding layer and underlying diffusion layer, which decreases MBN [ 16 , 17 ]. MBN decreases along with the increasing thickness of the non-ferromagnetic layer on the surface (and/or hard ferromagnetic) [ 16 ] as a result of superimposing effects clearly explained in previous studies [ 12 , 17 ].…”

“…Magnetic Barkhausen noise (MBN) has already been reported as a suitable technique for similar purposes [ 12 , 13 ]. It was reported that MBN can provide information about the Zn galvanizing process of wires [ 12 ].…”

“…Magnetic Barkhausen noise (MBN) has already been reported as a suitable technique for similar purposes [ 12 , 13 ]. It was reported that MBN can provide information about the Zn galvanizing process of wires [ 12 ]. This technique was also employed for monitoring coating heterogeneity in the case of steel S460MC [ 13 ].…”

Examining Ferromagnetic Materials Subjected to a Static Stress Load Using the Magnetic Method

“…I the Barkhausen noise method relies on observing the magnetization process, which causes the dipoles to rotate [14][15][16]. If the material contains inhomogeneities, the process of domain wall shifting will be disrupted.…”