Relation between residual stress and Barkhausen noise in a duplex steel

The relation between residual stress and Barkhausen noise (BN) was evaluated in a duplex stainless steel. The residual stresses had been created to the test piece by local heating. Rms value, position of the maximum of the BN burst, its full width half maximum, power spectrum and pulse height distribution were characterised. All the parameters depended to some extent on the residual stresses and none of them was totally independent on the other parameters. The best parameter for the residual stress evaluation was the rms value of the BN amplitude. The rms value varied according to the total stress (macrostress+homogeneous microstress) in the ferrite phase. The stress component perpendicular to the direction of the magnetization had also some influence. Based on the results it is possible to evaluate the residual stresses of the ferrite phase of duplex stainless steels by the BN method.