Measurement of Residual Stresses of The Welded Carbon Steel Plate by Magnetic Method Using Contact Type Sensor

Abstract

Magnetic nondestructive evaluation technique, Barkhausen noise(BHN) analysis was applied to measure the residual stresses of the welded components. BHN was detected by a contact type sensor scanned on the surface of the bead-welded carbon steel plate. In order to investigate only the contribution of residual stresses on BHN, two tests for changing the internal residual stresses, applied tensile load test and stress release by sectioning, were tried. BHN value changed very much similarly with strain change corresponding to the variation of residual stress at each point of welded part. BHN method also succeeded in monitoring the annealing effect for the welded part.