Correlation of Magnetic Barkhausen Emission Profile with Strength of Thermally Degraded 2.25Chromium–1Molybdenum Steel

Abstract

A non-destructive magnetic Barkhausen emission (MBE) technique was applied to assess thermal degradation of 2.25Cr–1Mo steel, exposed to 630°C for up to 4800 h. The peak position and the peak amplitude in MBE profile decreased and increased, respectively, as a linear function of cube root of isothermal degradation time. These changes in MBE profile were related to the carbides coarsening during thermal exposure. An empirical correlation between the ultimate tensile strength (UTS) and the peak position in the MBE profile was also obtained by a linear regression analysis.