Fine structure formation in rails under ultra long-term operation

Ivanov, Yu. F.; Глезер, А. М.; Kuznetsov, R. V.; Громов, В. Е.; Shlyarova, Yu. A.; Семин, А. П.; Сундеев, Р.В.

doi:10.1016/j.matlet.2021.131378

Cited by 9 publications

(5 citation statements)

References 7 publications

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“…The crystal lattice bend can be [3,7,8,12,14]: a) purely elastic, created by stress fields accumulated due to deformation incompatibility, for example, polycrystal grains, material matrix and non-deformable particles; b) plastic, if the bend is created by dislocation charges, i.e. an excess density of dislocations localized in a certain volume of the material, and c) elastic-plastic, when both sources of fields are present in the material.…”

Section: Determination Of Internal Stresses By Temmentioning

confidence: 99%

“…The sources of internal stresses of elastic origin, which arise mainly during inhomogeneous deformation of the material, are, first of all, microcracks [3,7,8,25]. Another source of internal stress is the Bain distortion [12], which occurs as a result of the curvature of the crystal lattice during Ȗ ĺ Į phase transformation in steels.…”

Section: Sources Of Internal Stresses In Bcc Steelsmentioning

confidence: 99%

“…Such stresses also arise in materials strengthened by dispersed non-deformable particles [14]. In the case of partial relaxation of these fields by multiplication and slip of dislocations, they acquire an elastic-plastic character [7,8,25]. Depending on the degree of their interaction with the surrounding dislocation structures, the resulting internal stresses can be of all three types.…”

Section: Sources Of Internal Stresses In Bcc Steelsmentioning

confidence: 99%

“…The problem of internal stresses in metals and alloys has been at the center of attention of researchers for many years [1][2][3]. This is explained by the fact that internal stresses play an important role in the formation of the yield stress, strain hardening [4][5][6][7] and especially in the fracture of crystalline materials, namely, in the initiation and opening of microcracks [8][9][10][11]. Their role is great in the evolution of the defect structure in various types of heat treatment of metals, alloys, and steels [12].…”

Section: Introductionmentioning

confidence: 99%

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Formation of microscopic internal stresses in rails during long-term operation

Gromov,

Porfiryev,

Kryukov

et al. 2023

cisisr

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The level of microscopic internal long-range stress fields ı l on the rolling surface and the working fillet is determined for two categories of rails with a carbon content of 0.74 wt. % and 0.91 wt. %. DT350 for general purpose and DT400IK of increased wear resistance and contact endurance after the passed tonnage of 1,770 mln. t (for DT350) and 187 mln. t DT400IK (1) and 234 mln. t of DT400IK (2). For this purpose, the bending extinction contours were analyzed by means of transmission electron diffraction microscopy, the parameters of which were used in calculating ı l . The presence of excess extinction contours indicates the bending-torsion of the lattice, which is characterized by the excess density of dislocations. A comparison is made with other methods for measuring internal stress fields at the meso-and macro levels. It is shown that the parameters of the bending extinction contours are the most informative and allow one to control the locality of the measurement ı l . Sources of internal stress fields in rail steels are noted. An increase in the level of ı l was revealed in DT400IK rails in comparison with DT350 rails. The growth of the passed tonnage for rails of category DT400IK leads to an increase in ı l , the values of internal stresses on the fillet surface exceed the corresponding values on the rolling surface. The physical causes of the observed changes are discussed.

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Section: Determination Of Internal Stresses By Temmentioning

confidence: 99%

Section: Sources Of Internal Stresses In Bcc Steelsmentioning

confidence: 99%

Section: Sources Of Internal Stresses In Bcc Steelsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Formation of microscopic internal stresses in rails during long-term operation

Gromov,

Porfiryev,

Kryukov

et al. 2023

cisisr

View full text Add to dashboard Cite

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“…should be based on the knowledge of the mechanisms of the structural and phase changes and fine substructure under deformation. The mechanisms of rail strengthening at different volumes of the passed tonnage were evaluated in [24][25][26], and the evolution of lamellar pearlite of rail steel under compression deformation was analysed in [27].…”

Section: Introductionmentioning

confidence: 99%

Strengthening Mechanisms of Rail Steel under Compression

Ivanov,

Porfiriev,

Gromov

et al. 2023

Metals

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The evolution of the structure–phase states and the dislocation substructure of rail steel under uniaxial compression to the degree of 50% was studied by transmission electron microscopy. The obtained data formed the basis for a quantitative analysis of the mechanisms of rail steel strengthening at degrees of deformation by compressions of 15, 30, and 50%. Contributions to the strengthening caused by the friction of the matrix lattice, dislocation substructure, presence of carbide particles, internal stress fields, solid solution and substructural strengthening, and pearlite component of the steel structure were estimated. Using the adaptivity principle, which assumes the independent action of each of the strengthening mechanisms, the dependence of the rail steel strength on the degree of plastic deformation by compression was estimated. A comparative analysis of the stress–strain curves σ(ε) obtained experimentally and calculated theoretically was performed.

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