Comparison of Properties of Magnetoacoustic Emission and Mechanical Barkhausen Effects for P91 Steel After Plastic Flow and Creep

The correlation between magnetoacoustic emission intensity and mechanical Barkhausen effect intensity has been tested in the case of P91 steel having different microstructure states due to either plastic flow at room temperature or speeded-up creep, performed under stress 290 MPa at temperature 773 K. The plastic strain range for the first set of samples has been from 2.0% up to 10.5% and for the second one from 0.85% up to 10.0%. Both effects revealed analogous monotonous decrease of their intensities as a function of resulting plastic strain. The decrease was higher for plastic flow than for creep. Those results are well consistent with results of tensile tests of the as damaged samples.