<p>Variations of the structural parameters, as well as physical and mechanical properties of ferromagnetic materials, are reliably monitored by the methods of magnetic structuroscopy. For this purpose, it is customary to use the internal demagnetization coefficient of the material, which depends on the mechanical stresses, structural inhomogeneities, and anisotropy of the material. However, in order to determine the internal demagnetization coefficient of the material, it is necessary to perform a&#xa0;cycle of anhysteretic magnetization of thermally demagnetized material with precision measurements of its magnetization and subsequent statistical processing of the results of measurement, which decreases the reliability and complicates the use of this coefficient in magnetic structuroscopy. Thus, in analyzing the relationship between the internal demagnetization coefficient of the ferromagnetic material and the parameters of its saturation hysteresis loop, we propose to use an indirect procedure of determination of the internal demagnetization coefficient according to its coercivity, remanent magnetization, and technical saturation magnetization based on the formulas deduced earlier by the author. The influence of the modes of heat treatment, chemical composition of steels, and the relationship between their magnetic parameters on the structural heterogeneity of studied materials is analyzed. We present an example of analysis of the functional dependences and the range of possible variations of the internal demagnetization coefficient of the material depending on the changes in its magnetic parameters in practically important ranges. The influence of the carbon content of carbon steels on their internal demagnetization coefficient is studied. As an example, for the heat-resistant medium-carbon 34CrMo4 alloyed steel extensively used in machine-building (in the production of forgings and fittings), we determined the range of quenching temperatures within which the structural heterogeneity of quenched steel is maximum. It is shown that, in the entire range of changes in the tempering temperature of 34CrMo4 steel after quenching, the dependence of the internal demagnetization coefficient on this temperature is monotonic. As a&#xa0;result of our investigations, it is demonstrated that the indirect procedure of determination of the internal demagnetization coefficient according to the proposed formula gives its values that can be recommended for the nondestructive testing of structure and the parameters of thermal treatment of medium-carbon alloyed steels.</p>