S. M. Zadvorkin

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.

The influence of an elastic uniaxial deformation of a medium-carbon steel on its magnetostriction in the longitudinal and transverse directions

In order to reveal the role of magnetostriction in the formation of a magnetic texture that appears in steels during their elastic deformation, the influence of stresses during uniaxial loading on the behavior of several magnetic characteristics of medium-carbon steel 45 was investigated. The magnetic parameters were measured under the conditions of a closed magnetic circuit with the application of attachable transducers along and across the direction of the applied load. The results of measurements of the hysteresis and magnetostriction properties of the investigated steel were compared. The magnetic parameters that monotonically change with an increase in the applied stresses were established.

The application of magnetic structural phase analysis for the diagnostics of the State of a 08X18H10T Steel-Ct3 Steel composite material and its components that were subjected to plastic deformation

The use of composite, in particular, multilayer materials, is one way to decrease the specific quantity of metal in an item and to increase its service characteristics. To develop methods for the diagnostic of the state of such composite materials and their components, the effect of cold rolling on the structure, magnetic, and mechanical properties of a two-ply composite material and its separate components was studied; the material was prepared by explosion welding of austenitic corrosion-resistant and low-carbon steels. It was shown that magnetic characteristics can be used for estimating the degree of deformation by rolling, phase composition, and mechanical properties of both two-ply 08X18H10T Steel-Ct3 Steel composite material as a whole and its separate components.

Possibilities of Nondestructive Testing of Physico-Mechanical Characteristics of Hypereutectoid Carbon Steels with the Structures of Isothermal Austenite Decomposition

The possibilities of estimating the hardness, the wear resistance under abrasive action and sliding friction, the impact strength, and the internal stresses of the U9 steel (with 0.94% of carbon) with the initial fine-lamellar pearlite structure annealed at 650°C during 2–600 min on the basis of magnetic and electrical characteristics, readings of an eddy-current instrument, and parameters of electromagnetic-acoustic conversion are studied. A comparative analysis of the magnetic, electromagnetic, strength, and tribological characteristics of the U10 and U15 hypereutectoid steels (with 1% and 1.53% of carbon, respectively) subjected both to isothermal treatment at 330–650°C (with formation of pearlite and bainite structures) and to additional short-time annealing at 650°C is carried out.

The influence of a preliminary plastic deformation on the behavior of the magnetic characteristics of high-strength controllably rolled pipe steel under an elastic uniaxial tension (Compression)

The influence of a preliminary plastic deformation, which models the initial stressed–strained state (SSS) of an article, on the behavior of the magnetic characteristics of pipe steel of the X70 (K60) strength class under elastic tension and compression was investigated. The magnetic characteristics of specimens were measured both under the conditions of a closed magnetic circuit and using attachable transducers along and across the applied-load direction. The prehistory in the form of plastic deformation has an effect on the regularities in changes in the magnetic parameters of a material upon the next elastic deformation as a consequence of plastic-deformation-introduced residual stresses of different levels. This indicates the necessity to consider the initial SSS of a metal structure when developing magnetic methods for determining the parameters of their SSS during operation.

The influence of the magnetoelastic effect on the hysteretic properties of medium-carbon steel during uniaxial loading

Hysteretic magnetic properties and longitudinal magnetostriction of planar specimens of air-hardened 45 steel were measured as functions of elastic tensile stresses along and perpendicular to the applied loading using a closed magnetic circuit and attachable transducers. Parameters that exhibit monotonic variations with increasing elastic tensile stresses, were found. It was shown that the maxima that were observed in the dependences of residual inductance and relative maximum magnetic permeability on applied stresses, as well as the minima that were observed in the dependences of the coercive force and demagnetizing current of an attachable electromagnet as measured with a sensor arranged along the tension axis on applied stresses, are related to the behavior of the magnetostriction curves of the steel under study.

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.

Physicomechanical properties and structure of the powder materials of the Fe-Si system

The integrated study of the structure and magnetic, electrical, and mechanical properties of the Fe-Si powder materials in a range of silicon concentrations 0–12 wt % showed that the dependence of all physicomechanical properties of these materials on the silicon content was related to the sequence of the formation of the disordered silicon solution in iron, ordered solution, and the Fe3Si phase.

Variation of magnetic properties of two-layer carbon-steel products under tension

Evolution of magnetic properties during tension of multilayer products have been studied on two-layer specimens composed of low-carbon and medium-carbon steel plates with different values of magnetic hardness. The magnetic properties were measured in a loaded state. A model of the stress-strain state of a two-layer specimen has been designed. A technique for restoring stress-strain curves of multicomponent steel products from magnetic characteristics of its components determined directly during tension has been suggested. The values of the field of the maximum magnetic permeability of the components have been recommended as a parameter for nondestructive testing of stresses and strains, namely, at small deformations, the field of the maximum magnetic permeability of the magnetically soft component and at higher deformations, the field of the maximum magnetic permeability of the magnetically hard component. The results obtained are of considerable interest for technical diagnostics of loaded two-layer elements of constructions, including surface-hardened, welded, and bimetallic ones.

Behavior of magnetic characteristics in promising nitrogen-containing steels upon elastoplastic deformation

We report on the studied influence of the applied normal and tangential stresses, as well as their combined effect on the structure, phase composition, and magnetic properties of three high-nitrogen steels (HNS). Two of the studied steels in the initial state had an austenitic structure and were diamagnetic. The third steel, according to the data of the X-ray diffraction and metallographic analysis, contained 7% δ-ferrite in its composition, which specifies its ferromagnetic properties. The nitrogen steels studied in this work have demonstrated the stability of the phase composition, as well as of the magnetic properties at various loading conditions, and, thus, can be used in the production of articles and elements of structures that are required to exhibit low magnetization and high stable magnetic characteristics under an applied force. Parameters that can be used as the informative ones when estimating changes that occur upon the production and exploitation of articles and elements made of HNSs with small contents of δ ferrite have been determined.