Nanosize Carbides Formation and Fatigue Life Increase of Stainless Steel by Electron Beam Treatment

Electron – beam treatment with 20 J/cm2 energy density of Fe-0.20C-23Cr-18Ni stainless steel increases fatigue life up to 2.1 times. Fracture surface investigations have been carried out by the methods of scanning and transmission diffraction electron microscopy and layer-by-layer analysis of structural phase states and defect substructure of steel subjected to the multicyclic fatigue tests, has been made as well. Nanosize (Cr,Fe)23C6 carbides formation and physical reasons of steel fatigue life increase by electron – beam treatment have been found out. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3480

Nanosize phases formation under low carbon steel thermomechanical strengthening

The quantitative regularities of structure phase states formation in different Hbeam cross sections under accelerated cooling in different regimes are established. The gradient structure-phase states formation being characterized by the regular change of dislocation substructure parameters, nanosized range -phase fragments and cementite particles on cross section are revealed by methods of transmission electron diffraction microscopy. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2068

Nanosize Structure Phase States of Ti Surface Layer Formed During Electroexplosive Carboborating

The electroexplosive carboborating leads to a significant (up to 12 times) increase in microhardness of the titanium irradiated surface. It is established that the thickness of strengthened surface layer reaches ~ 125 μm. The formation of nanosize structure-phase states in Ti surface layers during electroexplosive carboborating was carried out by methods of scanning and transmission diffraction electron microscopy. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3480

The structure and properties of a hypoeutectic silumin subjected to complex electron–ion-plasma processing

The layer-by-layer analysis of structural–phase states and tribological properties of hypoeutectic АК10М2Н-type silumin at the depth up to 170 μm after the complex processing is carried out by the state-of-the-art methods of physical materials science. It involves the electroexplosion alloying with titanium and yttrium-oxide powder in different ratios followed by electron-beam processing.Методами сучасного фізичного матеріалознавства проведено пошарову аналізу структурно-фазових станів і трибологічних властивостей доевтектичного силуміну марки АК10М2Н на глибині до 170 мкм після комплексного оброблення. Воно полягало в електропідривному леґуванні титаном і порошком оксиду ітрію в різних співвідношеннях з подальшим електронно-пучковим обробленням.Методами современного физического материаловедения проведён послойный анализ структурно-фазовых состояний и трибологических свойств доэвтектического силумина марки АК10М2Н на глубине до 170 мкм после комплексной обработки. Она заключалась в электровзрывном легировании титаном и порошком оксида иттрия в разных соотношениях с последующей электронно-пучковой обработкой

Modification of structure and surface properties of hypoeutectic silumin by intense pulse electron beams

Methods of contemporary physical materials science are applied for the analysis of structural and phase states, tribological and mechanical properties of hypoeutectic silumin treated by electron beams with parameters as follow: energy density — 10– 35 j/cm2, pulse duration — 10 μs, number of pulses — 3, pulse-repetition frequency — 0.3 Hz. The initial structure of silumin comprises grains of aluminiumbased solid solution, eutectic grains, inclusions of silicon and intermetallic compounds with different shapes and sizes.Методами сучасного фізичного матеріялознавства виконано аналізу структурнофазових станів, трибологічних і механічних властивостей доевтектичного силуміну, що піддається електронно-пучковому обробленню (ЕПО) за наступних пара метрів пучка: густина енергії — 10–35 Дж/см2, тривалість імпульсу — 10 мкс, кількість імпульсів — 3, частота проходження — 0,3 Гц. У початковому стані структуру силуміну сформовано зернами твердого розчину на основі алюмінію, зернами евтектики, включеннями кремнію й інтерметалідів різної форми та розмірів.Методами современного физического материаловедения выполнен анализ структурно-фазовых состояний, трибологических и механических свойств доэвтектического силумина, подвергнутого электронно-пучковой обработке (ЭПО) со следующими параметрами пучка: плотность энергии — 10–35 Дж/см2, длительность импульса — 10 мкс, количество импульсов — 3, частота следования — 0,3 Гц. В исходном состоянии структура силумина сформирована зёрнами твёрдого раствора на основе алюминия, зёрнами эвтектики, включениями кремния и интерметаллидов различной формы и размеров

Nanostructure Formation in Superior Quality Rails

Using transmission electron microscopy methods the layer by layer analysis of the bulk hardened superior quality rails is carried out and the quantitative parameters of structure, phase state and defect substructure gradients are established. The gradient character of changing of structure-phase states and dislocation substructure along the cross section of rail head is revealed. The oil bulk hardening of superior quality rails is accompanied by the formation of morphologically different structure, being produced according to the shear and diffusion of γ-α transformation. The base structure volume is formed by the diffusion mechanism and is consisted of plate pearlite grains, free ferrite grains and grains of ferrite-carbide mixture. The presence of the bend extinction contours testifying to curvature-torsion of crystal lattice is revealed on electron microscope images. The analysis of far acting internal field stresses created by interfaces of cementite plates of pearlite grains and interfaces of pearlite and ferrite grains is carried out. It is shown that the interface boundaries globular cementite particles-matrix are the possible places of microcracks initiation

Nanostructure Formation in Superior Quality Rails

Using transmission electron microscopy methods the layer by layer analysis of the bulk hardened superior quality rails is carried out and the quantitative parameters of structure, phase state and defect substructure gradients are established. The gradient character of changing of structure-phase states and dislocation substructure along the cross section of rail head is revealed. The oil bulk hardening of superior quality rails is accompanied by the formation of morphologically different structure, being produced according to the shear and diffusion of γ-α transformation. The base structure volume is formed by the diffusion mechanism and is consisted of plate pearlite grains, free ferrite grains and grains of ferrite-carbide mixture. The presence of the bend extinction contours testifying to curvature-torsion of crystal lattice is revealed on electron microscope images. The analysis of far acting internal field stresses created by interfaces of cementite plates of pearlite grains and interfaces of pearlite and ferrite grains is carried out. It is shown that the interface boundaries globular cementite particles-matrix are the possible places of microcracks initiation

Grazing-incidence Small-angle X-ray Scattering Technique for Probing Nanostructures and Processes at Nanoscale

The paper presents the grazing-incidence small-angle X-ray scattering technique and its application to the studies of self-assembly and re-assembly effects of colloidal nanoparticles. Two basic cases are exemplified - solvent evaporation driven self-assembly and self-assembly driven by barrier movement in the Langmuir-Blodgett trough. Studies of the nanoparticle re-assembly effects due to the surfactant removal complete the overview. These examples document strength of GISAXS for an in situ tracking of processes at nanoscale. The results have direct implications for tailored preparation of the self -assembled nanoparticle templates for sensing, plasmonics and other applications

Nanosize phases formation under low carbon steel thermomechanical strengthening

The quantitative regularities of structure phase states formation in different Hbeam cross sections under accelerated cooling in different regimes are established. The gradient structure-phase states formation being characterized by the regular change of dislocation substructure parameters, nanosized range -phase fragments and cementite particles on cross section are revealed by methods of transmission electron diffraction microscopy. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2068