COMPARATIVE STUDY WITH MAGNETIC TECHNIQUES OF P91 AND 13HMF STEELS PROPERTIES SUBJECTED TO FATIGUE TESTS

Boleslaw Augustyniak - Leszek Piotrowski - Marek Chmielewski - Zbigniew Kowalewski

   We report results of laboratory magnetic inspection of steel properties as a function of a number of fatigue test cycles. The following three magnetic properties have been tested: hysteresis loops of magnetic flux density, Barkhausen noise (BN) signal and magnetoacoustic emission (MAE) signal. Samples of ferritic/bainitic 13HMF and martensite like - P91 type steels had been loaded by MTS machine applying alternative stress with amplitudes of 230 MPa for 13HMF steel and of 350 MPa for P91 steel, respectively. Magnetic properties of both steels vary as a function of a number of fatigue cycles in quite a similar way (relative change of the order of 10%) but evidently the types of those dependencies are different. Those results are discussed qualitatively.

Keywords: Barkhausen noise, magnetoacoustic emission, fatigue tests, P91 steel, 13HMF steel

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