A hysteresis model considering microstructural feature distribution

A modified Preisach model with the Preisach function formulated based on microstructural feature distribution and probability theory, has been developed to model the major/minor loops of ferromagnetic steels. Ferrite grains and precipitates within the grains have been selected as the two independent microstructural features to demonstrate the model. The distribution of grain size, precipitate size and inter-particle spacing are introduced to formulate the Preisach function. Close fits between the modelled and measured major loops have been achieved for two ex-service power plant steels, which have ferritic microstructures containing carbide particles, for a preliminary validation of the model. The model has proved capable of modelling both major and minor loops considering microstructural feature distributions