Micromagnetic Determination of Thermal-Induced Residual Stresses in Steel and White Cast Iron

Development of micromagnetic nondestructive method to estimate the thermally induced stress in multiphase magnetic system has been described in this paper. The method is based on interaction of magnetism and elastic strain. The effect of such interaction has been measured by magnetic Barkhausen noise. The interesting experimental observation is the variation of maximum Barkhausen noise with load. A maximum is observed at a particular stress that increases with the temperature. The reversibility and reproducibility of Barkhouse noise under experimental condition are strong foundation to establish this alternative method for estmating the thermal stress. The method also permits qualitative determination of residual stress without the need for calibration using a reference method such as X-ray residual stress measurement. Hence it opens up a wide range of possible industrial applications.