Thermodynamic analysis using experimental magnetization data of the austenite/ferrite phase transformation in Fe–xNi alloys (x = 0, 2, 4 wt%) in a strong magnetic field

Abstract

The effect of a strong magnetic field on the transformation temperature from ferrite to austenite and from austenite to ferrite is examined in Fe–xNi alloys (x = 0, 2, 4 wt%). Alloy magnetization measurements are used to calculate the magnetic contribution to the driving force and to account thermodynamically for the field dependence of the transformation temperatures. The predicted shift of the transformation temperatures is compared with experimental dilatometry measurements of transformation temperatures, up to 16 T. The use of experimental magnetization measurements is found to be an accurate alternative to the Weiss molecular field theory for the prediction of the magnetization of ferrite close to its Curie point.