Optimizing Detection Parameters of Magnetic Barkhausen Noise Using Heat Affected Zone in Welded Ship Steel Plate

Abstract

Magnetic Barkhausen noise measurements on a welded marine steel plate were performed in a line that passes through the weld bead and extends to the base metal from both sides of the weld. The heat affected zone was characterized by a pattern in the peak height as a function of distance from the weld bead. Barkhausen noise profile analysis by extracting relevant parameters like peak position, profile area and profile half width was also performed. The result showed a clear variation in MBN profile parameters in a way similar to that of the profile peak height. It could be concluded that MBN profile parameters superimposed as a function of measurement distance from the weld bead may provide an accurate determination of the affected material near the weld bead. The variation in MBN profile parameters was enhanced by microstructural and mechanical changes along the measurement line. This experiment demonstrates that the Barkhausen noise profile parameters could be used to track various manufacturing and maintenance processes of steel instead of using a single parameter like the root mean square (rms) to eliminate the variability of results and narrow the tolerance of acceptance criterion.