Установлена существенная взаимосвязь высотных показателей шероховатости изношенной поверхности и относительной износостойкости поверхностных слоев сталей 25 и 50Г, модифицированных цементацией. Показано противоположное влияние температуры нагрева под закалку на износостойкость и шероховатость поверхности. Износостойкость цементованных сталей 25 и 50Г повышается закалкой от 1000°С вследствие изменения структурно-фазового состояния поверхностного слоя

Modern industry uses a lot of elements as additives to improve the service characteristics of metal products that are to be used for various purposes. These elements can be divided into two groups: the first group includes the elements interacting with iron and improving its characteristics (alloying elements), and the second group includes the elements, that modify the characteristics of the structure and properties in an undesirable direction. These are trace elements: S, P, O, As, and others in steel. The negative impact of these elements shows itself as banding, the formation of non-metallic inclusions, flakes, grain boundary segregations et al. The influence of the elements of the both groups on the properties of steel depends on the nature and level of interatomic interaction in the alloy. Computational and analytical study of the major impurity elements in steel impact on the interatomic bond strength and the probability of forming complexes, clusters, and chemical compounds with the basic alloying elements in the steel has been carried out in the work. The theoretical parameter which defines the strength of the ion-covalent bond of two atoms: non-metallic – metallic is the electronegativity of elements. The electronegativity difference of the metal and non-metallic elements increasing, the ionic bonding and thermodynamic stability of these compounds increase. On the other hand, concentration of valent electrons is a universal characteristic of an atomic element which determines many of its properties, and especially the energy of interatomic interaction. Energy calculations of pairwise interatomic impurity elements: H, C, N, S, P, As interaction with Fe and major alloying elements in steel: Mn, Cr, Si, V, Al, Ti, W, Cu, Mo, Nb were made. It has been stated that all the impurity elements except phosphorus, hydrogen and arsenic have sufficient high adhesion with the majority of the metal elements in the modern steels. Phosphorus does not form stable compounds with metals, but has a tendency to form grain boundary segregation (GBS). Niobium, molybdenum and titan change the nature of phosphorus distribution in steel and prevent GBS. Carbon, nitrogen and sulfur are impurity elements having higher energy of ion-covalent interaction with the main metals in steel, therefore tend to form clusters, complexes and chemical compounds.

The diffusion hardening steel can be produced in any plant having a thermal equipment, besides, it is more economical than obtaining an alloy steel with similar properties. The influence of the parameters of the diffusion of chromium plating (the composition of the steel, powder mixture) on the structure and mechanical properties of structural and tool steels was investigated. Results of X-ray analysis showed that the diffusion zone in the samples consists of two layers. First layer is predominantly carbides Cr 7C 3, Cr 23C 6, Fe 3C. An intermediate layer composed of carbon-free solid solution of chromium in the iron. The maximum total thickness of the diffusion zone is observed in the steel 130Cr12V1 and 130Cr12Mo1 (~80 µm), minimum in carbon steels 45, U10 (~10-30 µm). The thickness of carbide layer is approximately the same 1-3 µm. Analyzing of data micro-hardness measurement across the thickness of the diffusion zone it must be noted that the diffusion layers of the samples of the tool steels have a high micro-hardness 6000-10000. The maximum HV=10200 was in steel 30Cr2W8V1. Chromium saturation of steel surface significantly increases its wear resistance. A much greater effect of increase of coefficient of relative wear resistance (3 fold increase) was observed in steels 30Cr2W8V1, 130Cr12V1 and 130Cr12Mo1. The mathematical models relating the micro-hardness, wear resistance, the thickness of the diffusion layer were obtained. In view of the analytical relationships ascertained that the wear resistance of hardened steels substantially depend on the thickness of the diffusion coating, the microhardness of the layer and the core of steel and alloy steels has increased more than two times. For hardening steel punching tool 30Cr2W8V1 can be recommended composition of the powder mixture: 50% FeCr + 48% Al 2O 3 + 2% NaF, and for steel 130Cr12V1 preferably used as activator NH 4F

Carbide phase in the ironbased alloys plays a dominant role in shaping the physical and mechanical properties of steels for various purposes. Therefore, the study of its nature and properties is paid the great attention. The simplest carbides during cooling of double Fe-C alloys are released in the form of a compound Fe3C, the nature of which is not sufficiently studied. It is known that this phase is metastable and under certain conditions can break down into free carbon and iron atoms. In the present work, the characteristics of the formation of cementite on the assumption that the interatomic bond in it is ion-covalent nature, the level of which is determined by the difference in electronegativity Fe and C is investigated

Влияние режимов термической обработки на механические свойства опытной стали 06ГБД / М. А. Рябикина [и др.] // Інноваційні ресурсозбережні матеріали та зміцнювальні технології: матеріали Міжнар. наук.-практ. конф. 6-8 червня 2012, м. Маріуполь / ДВНЗ «ПДТУ». – Маріуполь, 2012. – С. 173-176.

Влияние ванадия, ниобия и титана на механические свойства стали P460NL1 / М. А. Рябикина [и др.] // Университетская наука-2012 : в 3 т. : тез. докл. междунар. науч.-техн. конф. (Мариуполь, 24-27 апреля 2012 г.) / ПГТУ. – Мариуполь, 2012. – Т. 1. – С. 177–179.

The results of experimental studies of the effect of cementation and subsequent hardening of different temperatures on the structure, hardness and abrasive wear resistance of steel (0,27 %C) and steel (0,55 %C, 1 %Mn) were submitted. The optimal technological regimes of hardening that improve durability steel (0,27 %C) ~ 3 times, and steel (0,55 %C, 1 %Mn) more than 4 times were determined

The influence of plate thickness normalized steels S355NL, alloyed with niobium, and niobium and vanadium on the mechanical properties was investigated. It was found that with the increase of plate thickness from 20 to 120 mm the level of mechanical properties of continuously decreased. The introduction of vanadium into steel causes the increase of the strength characteristics of steel, but it reduces the work of impact test at low temperatures.

Выбор режима термической обработки, обеспечивающего получение стабильного уровня механических свойств стали категории S355J2 / М. А. Рябикина [и др.] // Вісник Приазовського державного технічного університету : зб. наукових праць / ПДТУ. – Маріуполь, 2011. – Вип. 22. – С. 121–124. – (Серія : Технічні науки).

Влияние температуры нагрева под нормализацию на cтруктуру и механические свойства стали S355J2 / М. А. Рябикина, Ф. К. Ткаченко, В. Е. Ставровская, Т. Ю. Иванова // Университетская наука-2011 : в 3 т. : тез. докл. междунар. науч.-техн. конф. (Мариуполь, 17-19 мая 2011 г.) / ПГТУ. – Мариуполь, 2011. – Т. 1. – С. 194–195.

From the standpoint of electronic theory the features of the formation of grain-border segregation of alloying elements in binary alloys based on iron in the high-temperature region T>0.6 Tm were considered. The values of the binding energy of the atoms of the elements: Mn, Ni, Si, V, Al, Ti and Nb with the grain boundary were calculated and the level of their grain-border segregation СГ/С0 in binary Fe-Me solutions at 1100 K was estimated.

Влияние удельного времени нагрева при нормализации на структуру и свойства листового проката из стали S355J2 / Т. Ю. Иванова, В. Е. Ставровская, М. А. Рябикина, Ф. К. Ткаченко // Университетская наука-2011 : в 3 т. : тез. докл. междунар. науч.-техн. конф. (Мариуполь, 17-19 мая 2011 г.) / ПГТУ. – Мариуполь, 2011. – Т. 1. – С. 196–198.

By means of the established close link between the energy of self-diffusion activation and parameters of electron gas in pure metals, analytical dependences were obtained, which make it possible to determine by calculating the influence of temperature and composition upon grain growth inside Fe Mn alloys

Совершенствование химического состава стали для судостроения / М. А. Рябикина [и др.] // Вісник Приазовського державного технічного університету : зб. наук. праць / ПДТУ. – Маріуполь, 2009. – Вип. 19. – С. 106–108.

Влияние толщины листов на механические свойства проката из стали S355 / Т. Ю. Иванова [и др.] // Университетская наука-2009 : в 2 т. : тез. докл. междунар. науч.-техн. конф. (Мариуполь, 19-21 мая 2009 г.) / ПГТУ. – Мариуполь, 2009. – Т. 1. – С. 227–228.

Влияние температуры охлаждающей среды на структуру и механические свойства стали К60 / М. А. Рябикина [и др.] // Вісник Приазовського державного технічного університету : зб. наук. праць / ПДТУ. – Маріуполь, 2008. – Вип. 18, Ч. 1. – С. 99–102.