D. I. Vichuzhanin

Correlation between the stress-strain state parameters and magnetic characteristics of carbon steels

A method for reconstruction of the stress-strain diagrams of steel objects from their magnetic characteristics determined directly during tension has been suggested. The coercive force, residual induction in the major hysteresis loops, and the maximum magnetic permeability are recommended as parameters for nondestructive testing of stresses and strains.

Effect of Deviation from Coaxiality between the Directions of Magnetization and Mechanical Strain on the Results of Magnetic Testing of Elastic Strain in Steels

The magnetoelastic effect in steels that are in the states of coercive force and residual magnetization in the saturation hysteresis loop is studied. The regularities of changes in the residual magnetization and coercive force under uniaxial tensioning and compression of specimens of 30KhGSA steel magnetized along the direction of strain application are established. It is shown that a variation in the direction of magnetization and complication of the strain pattern result in considerable deviations in the character of changes in the magnetic forces determined by a ferroprobe-type coercive force meter for elastically strained plates from St3 and R6M5 steels and for an St3 beam.

Evolution of magnetic properties of Fe-Mn and Fe-Mn-Cr steels with different stability of austenite during plastic deformation

A complex of magnetic parameters of two-phase (γ+ε) and austenitic Fe-Mn and Fe-Mn-Cr steels subjected to elastic deformation by uniaxial tension and torsion at room temperature has been studied. Regularities of changes in both the magnetic properties of the steels with different composition and the deformation stability of austenite depending on the accumulated degree of deformation have been revealed.

Influence of uniaxial tension on magnetic characteristics of the 12ΓБ pipe steel exposed to hydrogen sulfide

The results of measurements of the magnetic characteristics of specimens of the 12ΓБ pipe steel subjected to treatment with hydrogen sulfide for 96–384 h and also in the initial state, which were performed directly under the conditions of applied uniaxial tensile stresses to the point of specimen failure, are presented. The influence of hydrogen sulfide for 96 h has almost no effect on the mechanical and magnetic properties of the 12ΓБ steel, whereas a longer exposure leads to an appreciable decrease in the metal plasticity and an increase in its strength characteristics and the coercive force. The dependences of the magnetic characteristics on the degree of deformation are qualitatively similar to the stress-strain diagram except for the initial region of loading, where the effect of induced magnetoelastic anisotropy is displayed. At the stage of elastic strains, an unambiguous correlation between the coercive force measured on a minor hysteresis loop in weak fields and tensile stresses was discovered, thereby allowing the use of this parameter for evaluating the elastic stresses in articles from the 12ΓБ pipe steel, including in conditions of the influence of a hydrogen sulfide medium on this steel.

Effect of laser surface hardening on magnetic characteristics of a carbon steel under loading

Comparative studies of the structure and mechanical and magnetic characteristics of a Steel 45 subjected to laser treatment and the same steel subjected to hot rolling and volume hardening were performed. Staging changes in magnetic characteristics during tension were shown to reflect the order of involvement of individual structural components into the plastic deformation of the material.

Studying recovery processes in a strain-hardened Al–Mg–Mn–Fe–Si alloy

The material of a shell structure subjected to 20-year use under ambient conditions has been studied. The structure and mechanical characteristics of a strain-hardened AMg6 alloy, as well as the effect of subsequent holdings of this alloy for 10–3000 h at temperatures of 50, 70, 80, 100, 130, 150, 180, and 220°C, on changes in its dislocation structure and mechanical characteristics have been investigated. It has been shown that, in the structures under study, the AMg6 alloy has a cellular structure with a high density of dislocations and the ultimate strength σu = 445.5 ± 2.5 MPa, the proof stress σ0.2 = 326.5 ± 3.5 MPa, and the relative elongation δ = 11.7 ± 0.5%. Polygonization in the alloy occurs at a temperature of 220°C and the initial stage of the recovery process corresponds to a temperature range of 50–100°С in which the softening process can be divided into two stages, i.e., stage (1) of active softening due to the interaction of point defects with each other and stage (2) of the stabilization of the characteristics of the alloy.

Peculiarities of deformation behavior of magnetic parameters of a maraging steel characterized by different degrees of precipitation hardening

The deformation behavior of the magnetic characteristics of maraging steel 03X11H10M2T (ЭП678), which is subjected to hardening followed by aging at temperatures of 400–580°C, is studied. Nonmonotonic variations of the coercive force in the elastic region are shown to result from two factors: the positive magnetoelastic effect and the presence of second-phase particles whose geometric size increases substantially with increasing aging temperature. Two-parameter nomograms are constructed that allow the current states of loaded structural elements made of the steel under study to be estimated from their magnetic characteristics.

Estimating the deformation state of single-and two-layer ferromagnetic materials on the basis of their magnetic characteristics

Magnetic characteristics measured along and perpendicularly to the tensile-stress direction for single-and two-layer specimens made of steel Ct3cΠ and steel 45 that were subjected to various heat treatments are studied at different degrees of deformation. Measuring the magnetic characteristics perpendicularly to the tension direction is shown to be more informative from the point of view of estimating the degree of deformation, while the use of a four-pole transducer allows determination of the direction.