Minor hysteresis loops measurements for characterization of cast iron

Structural variation in a series of cast iron samples was non-destructively characterized by means of sets of magnetic minor hysteresis loops. The flat samples were magnetized by an attached yoke, and reliable parameters were obtained from the series of minor loops, without magnetic saturation of the samples. It was found, that some magnetic quantities, well known to be closely connected to the samples’ structure variation, especially relative coercivity and remanent induction, could be distinguished more sensitively from minor loops, than from the major one.