MATERIALS OF THE KONSTANTINOVSKAYA CULTURE FROM THE TEMERNITSKOYE FORTIFIED SETTLEMENT

В 2017-2018 гг. на территории Темерницкого городища в центральной части г. Ростова-на-Дону было обнаружено поселение энеолитического времени (константиновская культура). В статье отдельно рассмотрены эти материалы, представленные в подавляющем большинстве керамикой и кремневыми изделиями (рис. 2-4). Часть их находилась в переотложенном состоянии - в разрушенном слое или хозяйственных ямах первых веков н. э. Оставшаяся половина найдена в нижних практически стерильных слоях предматерика и в заполнении двух выявленных рвов энеолитического времени (рис. 1). Единственный сохранившийся участок культурного слоя исследован в западной части раскопа. Именно с этого участка происходят два шила, обогащенная медная руда и несколько фрагментов неорнаментированных стенок сосудов с примесью раковины. Находки из металла (2 шила, плоская капля металла, медная руда) проанализированы на микрофлуоресцентном рентгеновском спектрометре (рис. 5). По совокупности технологических, морфологических и орнаментальных признаков керамики энеолитический слой Темерницкого городища можно атрибутировать ранним этапом константиновской культуры Нижнего Подонья. Помимо эпонимного поселения наиболее близки к найденным материалы нижнего горизонта Ливенцовского поселения и слой 6 поселения Раздорское I. К исследованным материалам энеолитического времени Темерницкого городища хронологически близким является погребение, обнаруженное на территории грунтового некрополя Темерницкого городища. In 2017-2018 an Eneolithic settlement (attributed to the Konstantinovskaya culture) was discovered in the territory of the Temernitskoye fortified site in the center of Rostov-on-the-Don. The paper considers these materials represented mostly_by ceramics and flint items (Fig. 2-4). Some of them were redeposited and found in a disturbed layer or household pits dating to first centuries AD. The remainder items were found in bottom and practically sterile layers over the virgin soil and in the fill of two identified Eneolithic ditches (Fig. 1). The only surviving section of the cultural layer was examined in the western part of the excavation area. It yielded two awls, enriched copper ore and several undecorated walls of shell-tempered vessels. Metal finds (two awls, a flat metal drop, copper ore) were analyzed by an X-ray microfluorescence spectrometer (Fig. 5). Based on technological, morphological and decorative characteristics of the ceramics, the Eneolithic layer of the Temernitskoye fortified settlement can be attributed to the early stage of the Konstantinovskaya culture of the Lower Don region. Besides the eponymic settlement, the materials retrieved from the lower horizon at the Liventsovka settlement and layer 6 from Razdorskaya I are the closest to the finds. A burial found in the necropolis of the Temernitskoye fortified settlement is chronologically close to the examined Eneolithic materials found at the Temernitskoye settlement.

Modeling the behavior of direct current electromagnetic forces acting on a drop of liquid metal during electroslag remelting

The article presents mathematical and computer modeling of the behavior of liquid electrode metal drops during the process of electroslag remelting (ESP) at a constant current source. The study of the effect of electric field created by direct current allowed us to show the deviation of the drop trajectory from the electrode axis. The flow of electrons and drops of the electrode metal are exposed to electromagnetic forces, which leads to their displacement relative to the remelted electrode axis. This effect entails destabilization of the liquid metal bath and crystal heterogeneity. In turn, the use of external influence on the flow of ESR process can make it possible to stabilize the liquid metal bath even with the use of direct current. Centrifugal forces can act as such forces. They can arise when implementing the technology with the consumable electrode rotation around its own axis. To establish the optimal parameters of rotation speed, it is necessary to estimate the magnitude of impact of the magnetic field that occurs during direct current remelting process. The modeling was carried out using the Ansys Fluent 16.0 software package on the example of remelting 12Kh18N10T steel under the flux ANF-6. The algorithm for calculating of Ansys Fluent is based on the finite element method. In this paper, the mathematical apparatus was not changed and was used in its initial form. The method of magnetic induction was used. The database of information about the ongoing process was built on a grid of finite elements with certain, but sufficient level of adequacy and quality. Each element contains information about the model at a given point, specified for this modeling process. We have revealed the change in the trajectory of the electrode metal drop by electric field from the opposite direction along which the drop flows. The average length of the path traversed by liquid metal drop from the mold axis to the inner surface is from 5 to 15 cm. The motion of an electrode metal drop without an external magnetic field was simulated. This simulation made it possible to determine (estimate) the direction of movement of electrode metal drops and the indicator of necessary external force to stabilize the liquid metal bath during ESP process at direct current equal to 0.067 N.

Some Peculiarities of MIG-MAG Welding Processes with Concentrated Energies

Throughout the history of modernization of welding processes, in many cases the research has focused on optimizing the location of energy in the welding area, with the continuous improvement of the quality of welded joints. The welding processes in shielding gas environment with fusible electrode (MIG-MAG) have achieved superior performances regarding the increase of the current density around of the welded joint, simultaneously with the increase of the universality degree of their application. This paper is based on researching the possibilities of concentrating energy in the welding area, seeking to obtain both more favorable energy yields and an increased quality of welded joints. In the paper are shown a some results obtained following a comparative study on 2 welding processes in MIG-MAG protective gas medium, differentiated mainly by the metal drop transfer mode: by spraying (Spray arc), respectively by synergistic transfer (Arc pulsed), applied for corner welding of alloy steel sheets.

Mass Transfer in Electroslag Processes with Consumable Electrode and Liquid Metal

Experimental and numerical comparisons of mass transfer processes during the electroslag remelting with consumable electrode (ESR) and electroslag refining with liquid metal (ESR LM) showed their identical refining capacity, despite the smaller both the slag–metal contact surface (twice) and metal overheat (by 70–95 K) in the latter case. As revealed, due to effect of metal movement inside the liquid metal drop, it moves in liquid slag faster than a solid particle of the same diameter. Under comparable conditions, it is experimentally confirmed that desulphurization at the ESR takes place mainly on the contact surface between the slag and metal baths, but not in the liquid metal film at the tip of a consumable electrode.

Determination of Parameters of Electrode Metal Transported Drops by Simulation and Visualization

The nature of the molten electrode metal melting and transfer is the main process parameter of manual metal arc welding (MMA) with coated electrodes. It significantly affects the efficiency of the welding process. For this reason the relevant task is to identify the parameters of the transferred molten electrode metal drops and their further transfer into the weld pool with maximum accuracy. The aim of the given paper is to develop a method and visual representation of the form and the geometrics (volume, area, mass) of a molten electrode metal drop.We have developed the method of simulation modeling and visualization for molten electrode metal drops transfer and their parameters. It allows obtaining highly reliable input data to be used for developing and verification of mathematical models for the thermal fields distribution along the welded item surface. The algorithm is realized as the calculation programs for specifying the molten metal drop parameters and means of its geometrics and space form visualization.We used this method to specify a number of molten electrode metal drop parameters: volume, mass, center-of-gravity position, surface area.We have established that it is possible to conduct the measurements with maximumThe suggested method significantly decreases the labor intensity of experimental studies aimed at specifying the size of electrode metal drops in comparison to the standard methods. When we know the size of the drops under certain welding conditions we can control the drop transfer process, i. e. reduce the heat input into the welded item and produce weld joints with the tailored performance characteristics.