№1(3) 2015

Постійне посилання зібрання

https://eir.nuos.edu.ua/handle/123456789/3335

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Перегляд №1(3) 2015 за Ключові слова "hardness"

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  • Ескіз
    Документ
    The 18H2N4MA steel strength characteristics increase = Повышение прочностных характеристик стали 18Х2Н4МА
    (2015-11-09) Dubovoy, A. N.; Дубовой, А. Н.; Volkov, G. V.; Волков, Г. В.; Zhdanov, A. A.; Жданов, А. А.
    The article considers the impact of prerecrystallization heat treatment on the hardness, strength and fatigue strength of the 18H2N4MA steel after preliminary shot blasting. It is experimentally established that as the result of prerecrystallization heat treatment at 500 °C with 3 minutes delay the layer with an increased measure of hardness (hardness is increased by 42 %) is formed on the 18H2N4MA steel surface after the preliminary shot blasting. The 18H2N4MA steel shot blasting causes the formation of compressive stresses in the surface layer, the subsequent prerecrystallization heat treatment does not change the nature of the residual stress, but only leads to the decrease in the absolute values, preserving the work-hardened layer depth. The prerecrystallization heat treatment leads to an increase in fatigue strength of the 18H2N4MA steel about 2.7 times compared with the shot blasting and increase of the tensile strength by 11 %, with plasticity indexes substantially constant. Such an increase in the strength indicators of the 18H2N4MA steel as a result of prerecrystallization heat treatment is caused by the formation of the substructures with shredded precinct in the steel surface layer. The given assumption is confirmed by the X-ray diffraction and electron metallography results. After prerecrystallization heat treatment the partial subgrains grinding from 222 ÷ 133 nm after shot blasting to 90 ÷ 49 nm is observed in the 18H2N4MA steel structure. = Исследовано влияние предрекристаллизационной термической обработки на предел прочности, твердость и усталостную прочность стали 18Х2Н4МА после дробеструйной обработки.
  • Ескіз
    Документ
    Influence of electric impulse impact on the mechanical properties of plasma coatings = Влияние электроимпульсного воздействия на механические свойства плазменных покрытий
    (2015-11-09) Dubovoy, A. N.; Дубовой, А. Н.; Karpechenko, A. A.; Карпеченко, А. А.; Bobrov, M. N.; Бобров, М. Н.; Novikov, A. A.; Новиков, А. А.
    The appliance of electropulse impacton the spraying distances to enhance the properties of plasma sprayed coatingsis discussed. The aim of research is to set the impact of high-voltage electrical pulses on the process of applying the plasma coatings and their mechanical properties.The structure and mechanical propertiessuch ashardness, bond strength, wear resistance of bronze plasma sprayed coating obtained using the electropulse impact are studied experimentally. Set the effect of The enhancement of mechanical properties of coatings obtained by grinding their structure and improving the speed of sprayed particles are set. The research results can be applied in thetechnology of repair and restoration of machines elements and mechanisms.The fixed effect allows us solving the problem of providing the high quality plasma sprayed coatings. = Исследовано влияние наложения электрических импульсов при плазменном напылении на механические свойства покрытий.