Phase Composition Using a Variable Magnetic Field

Abstract

In the present work the application of the variable magnetic field to investigate the composition of phases present in the alloys is presented. In order to make a study in the variable magnetic field a prototype apparatus was performed. The magnetic leakage of the alloy (k_s) was measured in the reversible range of magnetic field.
Experimental tests were conducted on samples of Fe–Cu alloys have contained the different volume fraction of phases components. Comparison of volume fraction of the solid solution α_Fe determined by weight and magnetic methods was performed. The linear dependence between the magnetic coupling and the volume fraction of phases components was observed. This observation can be used to estimate the quantitative phase composition in a biphase alloys. It has been shown that in the reversible range of the magnetic field, the magnetic leakage of the alloy is equal to the sum of products of volumetric proportions of individual phase components and their magnetic leakage.
In the present work a new method for quantitatively assessing the phase composition using a variable magnetic field is presented which is universal for two-phase alloys if the two phases have different magnetic leakage. This can be particularly useful for assessing the proportion of austenite and retained austenite in heat-treated alloys of iron and carbon.