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EN
The main purpose of processing of tough-to-machine materials is improving of cutting process of steels with different physicochemical properties and alloying by means of various chemical elements in combination with heat treatment. Producing of high quality surface layers depends on properties of material used to make details, that is why reasons of tough machining were identified: influence of chemical composition and resulting structure. The studies of grinding of tough-to-machine materials were undertaken by means of grinding wheels made from synthetic diamonds as they are most resistant and highly-productive. Based on the studies recommendations for using of characteristics of grinding wheels and tough-to machine steel grades are given. Research on heat processes during grinding allows us to determine patterns showing how cutting speed, detail motion speed, area and action period of contact influence temperature and speed of heat processes in surface layers as well as depth of heating. These patterns also give the chance to show interrelation between temperature and rate of heating and cooling. This gives an opportunity to predict state of structure of surface layer of details made of tough-to-machine steels under different machining conditions reasonably.
EN
Cost-efficient, enabling technologies for keeping and increasing the reservoir recovery rate of oil-formations with high water cut of produced fluids and exhausted resource are really essential. One of the easiest but short-term ways to increase oil production and incomes at development of oil deposits is cost of development and capital cost reduction. Therefore, optimal choice and proper feasibility study on the facilities for multilayer oil fields development, especially at the late stage of reservoir working, is a crucial issue for now-day oil industry. Currently, the main oil pools do not reach the design point of coefficient of oil recovery. The basic feature of the late stage of reservoir working is the progressing man-made impact on productive reservoir because of water injection increasing for maintaining reservoir pressure. Hence cost-efficient, enabling technologies for keeping and increasing the reservoir recovery rate of oil-formations with high water cut of produced fluids and exhausted resource are really essential. To address the above concerns the dual completion petroleum production engineering was proposed. The intensity of dual completion of formation with of different permeability is determined by rational choice of each of them. The neglect of this principle results a disproportionately rate of highly permeable formations development for the time. In effect the permeability of the formations or their flow rate is decreasing. The problem is aggravated by lack of awareness of mechanics of layers' mutual interference in producers and injectors. Dual completion experience in Russian has shown, that success and efficiency of the technology in many respects depend on engineering support. One of the sufficient criteria for the choice of operational objects should be maximal involvement of oil-saturated layers by oil displacement from seams over the economic life of well producing oil. If it is about getting high rate of oil recovery for irregular formations there is no alternative to dual completion and production. The recommended dual completion petroleum production technology enables development several formations by single well at the time. The dual completion petroleum production technology has been more important than ever because it is right not only for formations but for thin layers with undeveloped remaining reserves.
EN
The paper presents the results of experimental studies of the evolution of the homogeneity of the crystallographic texture and deformation behavior in bulk Cu and Ti billets subjected to the different numbers of equal-channel angular pressing (ECAP). It is found that the 1st pass during ECAP of pure Cu and Ti results in the formation of the pronounced preferred orientation of crystallites. Increase of the number of ECAP passes is accompanied by the formation of pronounced texture maxima which are orderly arranged in the pole figure. The intensity of texture maxima corresponding to the central part of the billet is the highest. The heterogeneity of the deformation behavior grows significantly after the 1 st ECAP pass as compared to the initial state, but it reduces with the increasing number of ECAP passes.
PL
Artykuł przedstawia wyniki badań eksperymentalnych nad rozwojem jednorodności tekstury krystalograficznej I postępu deformacji w prętach Cu I Ti poddanych cyklicznemu odkształceniu metodą przeciskania przez kanał równo-kątowy (ECAP). Stwierdzono, że w czystej Cu i Ti podczas pierwszego przepustu ECAP formuje się wyraźna uprzywilejowana orientacja krystalitów. Wraz ze wzrostem liczby przepustów ksztaltują się składowe tekstury, które są coraz bardziej stają się wyraźniejsze w postaci maksimów na figurze biegunowej. Największa intensywność tekstury występuje w obszarach zlokalizowanych w centralnej części przekroju poprzecznego odkształcanego pręta. Jednorodność postepującej deformacji po 1-wszym przepuście ECAP zwiększa się znacząco w porównaniu ze stanem wyściowym z tym, że po każdym następnym przepuście zostaje osłabiana (szczególnie w Ti).
4
Content available remote Formation of crystallographic texture during severe plastic deformation
EN
The current paper represents the results of recent investigations, aimed at revealing of regularities and establishing of crystallographic texture evolution mechanisms during equal-channel angular pressing (ECAP). Pure Cu was used as material for investigation. The investigations were conducted with the help of computer simulation. The variable parameter was the friction coeffcient. Accumulated strain fields, as well as strain rate gradients, were calculated using the variation-diffrence method (VDM) and the simplest isotropic material model. The strain rate gradients from the VDM program served as input parameters for the viscous-plastic self-consistent model (VPSC), simulating the texture formation processes. Results of modeling are compared to experimental texture measurements.
PL
W pracy przedstawiono wyniki najnowszych badań dotyczących prawidłowości mechanizmu formowania się tekstury krystalograficznej czystej miedzi podczas wyciskania w kanale kątowym (ECAP). Parametrem zmiennym był współczynnik tarcia. Badania wsparto symulacją komputerową. Za pomoca metody wariacyjno-różniczkowej (VDM) oraz uproszczonego modelu materiału izotropowego obliczono skumulowane pola odkształceń i gradienty prędkości odkształcenia. Gradienty prędkości odkształcenia z programu VDM posłużyły jako parametry wejściowe dla samouzgodnionego, visko- plastycznego modelu (VPSC) symulującego proces formowania się tekstury.Wyniki modelowania porównano z doświadczalnymi pomiarami tekstury.
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