A. A. Osipov

Magnetization distribution along the cylindrical rod in longitudinal constant uniform magnetic field

The known analytical expressions and experimental data obtained by the authors on the distribution of the cross-section-averaged relative magnetization along a longitudinal solid cylindrical rod magnetized by the uniform field are analyzed. A new calculation formula is offered whose distinctive feature is the allowance for the dependence of the material magnetic characteristics on the field magnetization. Results of calculations and experiments for rods with different geometric parameters and material magnetic characteristics are compared. The applicability of the formula is shown.

Induced magnetic anisotropy in low-carbon steel plates subjected to plastic deformation by stretching

Experimental studies of induced magnetic anisotropy in plastically deformed low-carbon steel were carried out. The measurements were performed on samples in the form of discs. The maximum energy of the induced magnetic anisotropy was observed at a relative elongation of ~12% upon an increase in the plastic deformation of samples. At higher degrees of deformation the energy of the induced magnetic anisotropy is reduced, which indicates a decrease in the residual mechanical stresses in the material.

A setup for measuring the magnetic characteristics of soft magnetic materials and articles

An automated setup for measuring the normal magnetization curve, the major and minor magnetic-hysteresis loops, and the main (initial permeability, maximum permeability, residual magnetic induction, induction coercive force, and saturation induction) and additional (the permeability at a field equal to the coercive force, the field strength at which the saturation induction is reached, and the induction at fields equal to the coercive force and the double coercive force) magnetic parameters of soft magnetic materials and articles produced from them is described. Measurements are performed in an open or closed magnetic circuit at a magnetization-reversal frequency of 0.05–0.5 Hz. The block diagram of the setup and its main parameters and characteristics are presented. The operation of the setup and the possibilities of its application are considered.

IMA-4M pulsed magnetic analyzer

The effect of the instability of the rear edge of magnetizing pulses on the results of testing by means of the pulsed magnetic method is considered. A description is given for a new IMA-4M device for magnetic testing of products fabricated from low-carbon steels and certain middle-carbon and low-alloy cold-rolled and hot-rolled steels of thickness up to 4 mm. A box-diagram and technical characteristics of the device are given.

The IMA-6 pulsed magnetic analyzer

The principle of construction of the IMA-6 pulsed magnetic analyzer for testing the quality of thermal treatment, the mechanical properties, and the microstructure of articles of low-carbon, medium-carbon, and low-alloyed cold- and hot-rolled steels is described. The structural scheme, the performance characteristics, and examples of application of the instrument are presented.

Distribution of residual magnetic induction along a solid circular core magnetized in longitudinal constant homogeneous magnetic field

An amalysis of the data obtained experimentally and by numerical computation on the distribution of residual magnetic induction averaged in a cross section along the longitudinal axis of a solid circular core magnetized by a constant homogeneous magnetic field is given. A new calculation formula that takesinto account the dependence of the magnetic material characteristics on the value of the magnetizing field is proposed. The calculation and experimental data are compared for cores with various geometries and magnetic material characteristics. The area of applications for the formula is shown.

Distribution of Magnetic Induction Along Hollow Core of Round Section in Constant Homogeneous Magnetic Field

The results and an analysis of experimental studies of the distribution of the average relative magnetic induction in the cross section along the longitudinal axis of a hollow cylindrical ferromagnetic core of a round section magnetized by a homogeneous constant magnetic field are presented. A new formula is presented for calculations that take into consideration the thickness of the wall of the core and the dependence of the magnetic characteristics of its material on the size of the magnetizing field. A comparison has been made of the results of calculations and experiments for hollow cores of different geometries and the various magnetic characteristics of a material in a wide range of changes in the magnetizing field. The scope of the formula is shown.

Central demagnetization coefficient for hollow cylindrical bars made of soft magnetic materials

A new formula is proposed for calculation of the central demagnetization coefficient for hollow cylindrical bars made of soft magnetic materials. The nonuniformity of the demagnetizing field was taken into account by means of averaging, over the volume, the density of fictitious magnetic charges on the surface of the hollow bar and using an empirical expression for the magnetization distribution over the surface. The calculations performed according to the proposed formula are compared to experimental data, including those obtained by other authors. The new formula is shown to be applicable to the calculation of the central demagnetization coefficient for hollow cylindrical bars made of soft magnetic materials in a broad range of bar dimensions.

A procedure and device for calibration-free determination of residual compression stresses in low-carbon steels deformed by tension

A procedure for determining the residual compression stresses in tension-deformed low-carbon steels has been proposed that does not involve pre-calibration of the device with standard samples for the case where magnetic anisotropy is mainly determined by mechanical compression stresses. A new design of the attachable measuring transducer is presented for experimental determination of the induced magnetic-anisotropy field within local areas of lump ferromagnetic objects. The legitimacy of evaluating compression stresses with this procedure has been proved experimentally.

Distribution of the residual magnetic induction along a hollow cylindrical core magnetized by a longitudinal homogeneous static magnetic field

Experimental and numerical data on the distribution of the cross-section-averaged relative residual magnetic induction along the longitudinal axis of a hollow cylindrical core magnetized by a homogeneous static field obtained by the authors were analyzed. A new calculation formula was proposed. A distinguishing feature of this formula is that it takes into consideration the thickness of the core’s wall and the dependence of the magnetic properties of the material on the magnetizing field. A comparison between the numerical results and the experimental data for cores of different geometries manufactured of materials with different magnetic properties was made. The application area of the proposed formula was shown.