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1
Content available remote Technologie cięcia w produkcji kanałów wentylacyjnych z blach powlekanych
PL
W niniejszym artykule autorzy analizują technologie cięcia blach i taśm stalowych ocynkowanych wg PN-EN 10346:2015-09 [1] w gatunku DX51DZ275-M-A-C [2], o wydatku ocynku 275 g/m2. Wykorzystuje się je do produkcji różnego rodzaju kształtek wentylacyjnych prostokątnych i kanałów. Materiały o grubości w zakresie od 0,6 do 1,5 mm stosowane do produkcji muszą spełniać wymagania normy PN-89/H-92125.
EN
In this article, the authors analyse the technologies of cutting galvanized steel sheets and strips according to PN-EN 10346:2015-09 [1] in the grade DX51DZ275-M-A-C [2], with the galvanizing coating of 275 g/m2. They are used for the production of various types of rectangular ventilation fittings and ducts. Materials with a thickness in the range from 0.6 to 1.5 mm used for production must meet the requirements of the PN-89/H-92125 standard. The process of cutting, i.e. the loss of material consistency, consists in mechanical or thermal impact on the material until it is cut or burned through its entire thickness.
EN
Watercourses serve the needs of agriculture in certain sections and are subject to strong anthropopressure. When agriculture prevails in the catchment, it often has abundant vegetation, macrophytes in particular, and the bottom is covered by a substantial layer of silt. In order to ensure patency of flow and access to water, small watercourses are very often subject to river maintenance works. The aim of the study was to assess the impact of 3 types of works on the diversity of fish species and density of fish in the 1 and 2 year after the works at 21 sites located on 8 rivers in the European Central Plains Ecoregion. As a result of the works, especially in the 1 year after the works, significant changes were found in hydrochemical and hydrological parameters, especially with the increase in velocity and mean depth in watercourses. Additionally, habitat change contributed to differences in the composition of the ichthyofaunal. After 1 year, the diversity of fish species and fish population density increased or remained unchanged after dredging and removal of plants from the river channel, but they decreased after the removal of macrophytes from river banks. After year 2, a decrease in the diversity of fish species and density was observed, associated with re-infestation and siltation of the watercourses. Particularly in the case of dredging and removal of macrophytes from the river bank, maintenance works should not be done too frequently, because some species of natural value disappear.
EN
Purpose: Machining silicon carbide (SiC) is challenging due to its brittle and maximum tensile nature. Lapping or laser beam are done with a high cost of manufacturing and low material removal rates. Water abrasive jet cutting is a promising candidate since the machining temperatures and processing force of ceramics are extremely low. Investigation into the abrasive water jet machining of silicon carbide is carried out in the present work. Design/methodology/approach: The variations in traverse speed while abrasive water jet cutting of silicon carbide and its effect on the surface roughness and kerf characteristics are studied. Silicon Carbide abrasive material is used as garnet consisting of 80 mesh. The surface roughness was calculated along with the depth of the cut made during the processing. Findings: The outcomes demonstrated that the traverse speed is more effective upon the surface roughness and is an important factor that damages the top kerf width and the kerf taper angle. Research limitations/implications: Based on the hardness and thickness of the SiC plate, the taper angle is high, and for a feed rate of 10 mm/min, the surface roughness is low. Less thickness of the SiC plate could have a lower taper angle than with high thickness. The erosive force is provided by abrasive material along with the jet stream. Practical implications: Water abrasive fine jet could effectively machinate silicon carbide ceramic material with a better surface finish accurately. Suitable surface roughness with higher productivity can be attained with medium traverse speed. Originality/value: The effect of process parameters on kerf taper angle and top kerf width in the abrasive water jet machining of silicon carbide is explored, considering surface roughness as an important output parameter.
EN
The article presents results of tests concerning the effect of technological parameters of the plasma arc cutting process (involving the use of air as plasma gas) on the quality of cut surfaces as well as on structural transformations and changes in the chemical composition of 14 mm-thick plates made of steel S235JR. The tests revealed that the adjustment of optimum parameters of the cutting process enabled the obtainment of cut surfaces representing quality class I in accordance with the ISO 9013 standard. Only the surfaces processed using the maximum cutting rates represented quality class II. The chemical composition analysis was performed using an ICXA 733 X-ray microanalyser (Jeol) equipped with an energy-dispersive spectrometer (EDS) and an ISIS 300 analytical system (OXFORD). The cut surfaces were observed and their characteristic areas were photographed using an X-ray microanalyser and the backscattered electrons (BSE) technique. The phase analysis was performed using a PHILIPS PW 1050 X’Change machine operated in the B–B (Bragg–Brentano) geometry. It was observed that the application of the air plasma cutting process led to the formation of an amorphous phase on the cut surface. The amorphous phase was characterised by a very high nitrogen content (of approximately 1.6%) and a hardness of 750 HV 0.2. The intense nitration resulted from the diffusion of nitrogen from the plasma gas. At the same time, the effect of air plasma arc gases on the liquid metal was responsible for the carburising of the cut surface (up to approximately 0.5%) and the burnout of alloying components (in accordance with the theory of the selective oxidation of chemical elements). The quality of the cut surfaces was primarily affected by the cutting rate. An increase in the cutting rate was accompanied by the deterioration of the geometric features of cut surfaces. In addition, higher cutting rates also translated into the significant reduction of the HAZ width and that of the size of the zone of chemical composition changes. The tests revealed that, in terms of the 14 mm-thick plates made of steel S235JR, the optimum cutting rates were restricted within the range of 600 mm/min to 1500 mm/min. The tests carried out made it possible to determine the influence of the active plasma gas (oxygen, nitrogen) both on changes in the chemical composition of the tested steel and on the quality of the cut surfaces obtained.
EN
Based on comprehensive interrelated mathematical and graphical-analytical models, including 3D cut layers and simulation of contact, strain, force, and thermal processes during gear hobbing friction forces, heat fluxes, and temperature on the teeth of the hob surface are investigated. Various physical phenomena are responsible for their wear: friction on contact surfaces and thermal flow. These factors act independently of each other; therefore, the worn areas are localized in different active parts of the hob. Friction causes abrasive wear and heat fluxes result in heat softening of the tool. Intense heat fluxes due to significant friction, acting on areas of limited area, lead to temperatures exceeding the critical temperature on certain edges of the high-speed cutter. Simulation results enable identification of high-temperature areas on the working surface of cutting edges, where wear is caused by various reasons, and make it possible to select different methods of hardening these surfaces. To create protective coatings with maximum heat resistance, it is advisable to use laser technologies, electro spark alloying, or plasma spraying, and for coatings that provide reduction of friction on the surfaces – formation of diamond-containing layers with minimum adhesion properties and low friction coefficient on the corresponding surfaces.
6
Content available remote Technologia oraz linie do cięcia poprzecznego i wzdłużnego blach
PL
W artykule przedstawiono przebieg procesu cięcia mechanicznego za pomocą dwóch krawędzi tnących oraz zarys technologii i funkcjonalność linii do cięcia wzdłużnego i poprzecznego blach.
EN
The article presents the process of mechanical cutting with two cutting edges as well as the outline of the technology and functionality of lines for sheet metal cross-cutting and slitting.
PL
W niniejszym artykule autorzy analizują technologie cięcia blach i taśm stalowych ocynkowanych wg PN-EN 10346:2015-09 [1] w gatunku DX51DZ275-M-A-C [2], o wydatku ocynku 275 g/m2. Wykorzystuje się je do produkcji różnego rodzaju kształtek wentylacyjnych prostokątnych i kanałów. Materiały o grubości w zakresie od 0,6 do 1,5 mm stosowane do produkcji muszą spełniać wymagania normy PN- -89/H-92125. Proces cięcia, czyli utraty spójności materiału, polega na mechanicznym lub cieplnym oddziaływaniu na materiał do momentu jego przecięcia lub przepalenia na całej jego grubości.
EN
In this article, the authors analyse the technologies of cutting galvanized steel sheets and strips according to PN-EN 10346:2015-09 [1] in the grade DX51DZ275-M-A-C [2], with the galvanizing coating of 275 g/m2. They are used for the production of various types of rectangular ventilation fittings and ducts. Materials with a thickness in the range from 0.6 to 1.5 mm used for production must meet the requirements of the PN-89/H-92125 standard. The process of cutting, i.e. the loss of material consistency, consists in mechanical or thermal impact on the material until it is cut or burned through its entire thickness.
PL
W artykule przedstawiono niekonwencjonalne metody przecinania materiałów konstrukcyjnych realizowanych we współczesnych procesach wytwarzania. Do tej grupy zaliczono przecinanie strugą wodną i wodno-ścierną a także przecinanie elektroerozyjne. Wskazano cechy pozytywne tych metod oraz kryteria jakimi powinno kierować się przy wyborze najlepszego sposobu przecinania.
EN
In this paper unconventional methods for cutting construction materials that are realized in modern manufacturing processes were presented. This includes cutting with water and abrasive-water jets and erosion treatment. It shall indicate their positive features and the criteria according to which the method should be selected.
EN
The paper reports experimental research on torques during cardboard cutting in the die-cutting press with eccentrics in the drive of the movable pressure plate. To conduct the research, an experimental bench with eccentrics in the drive of the die-cutting press is designed and manufactured. The manufactured experimental device for the research on cardboard blanks provides the possibility of getting dependencies of loadings at different parameters of the die-cutting process. The experimental approach envisages the use of the strain gauge measurement method and the wireless module for data collecting, as well as the software for its processing, for getting trustworthy results with minimum faults. The method gives an opportunity to study the torque values during the cardboard-cutting efforts on the drive shaft. The paper shows changes in the torque value on the drive shaft during the kinematic cycle with and without the use of cardboard blank. The angle of the drive shaft rotation during the cutting process was evaluated at selected values of the cardboard thickness. The relationship between the linear cutting efforts and the cardboard thickness, its fibre direction, cutting rule type and rotational speed of the drive shaft is elaborated. This kind of data is approximated by a logarithmic function (logarithmic curve), at R2 from 0.90 to 0.98. The thickness of the cardboard significantly influences the value of the linear cutting effort at all the studied parameters.
10
Content available remote Technologia oraz linie do cięcia poprzecznego i wzdłużnego blach
PL
W artykule przedstawiono przebieg procesu cięcia mechanicznego za pomocą dwóch krawędzi tnących oraz zarys technologii i funkcjonalność linii do cięcia wzdłużnego i poprzecznego blach.
EN
The article presents the process of mechanical cutting with two cutting edges as well as the outline of the technology and functionality of lines for sheet metal cross-cutting and slitting.
PL
W niniejszym artykule autorzy analizują technologie cięcia blach i taśm stalowych ocynkowanych wg PN-EN 10346:2015-09 [1] w gatunku DX51DZ275-M-A-C [2], o wydatku ocynku 275 g/m2. Wykorzystuje się je do produkcji różnego rodzaju kształtek wentylacyjnych prostokątnych i kanałów. Materiały o grubości w zakresie od 0,6 do 1,5 mm stosowane do produkcji muszą spełniać wymagania normy PN- -89/H-92125. Proces cięcia, czyli utraty spójności materiału, polega na mechanicznym lub cieplnym oddziaływaniu na materiał do momentu jego przecięcia lub przepalenia na całej jego grubości.
EN
In this article, the authors analyse the technologies of cutting galvanized steel sheets and strips according to PN-EN 10346:2015-09 [1] in the grade DX51DZ275-M-A-C [2], with the galvanizing coating of 275 g/m2. They are used for the production of various types of rectangular ventilation fittings and ducts. Materials with a thickness in the range from 0.6 to 1.5 mm used for production must meet the requirements of the PN-89/H-92125 standard. The process of cutting, i.e. the loss of material consistency, consists in mechanical or thermal impact on the material until it is cut or burned through its entire thickness.
12
Content available Neuromodel of the "Crusher mill" Mechatronic Complex
EN
To create a mechatron model of vacuum tube vibration system for rock cutting by flat auger tools based on physical and mechanical properties of processed array and kinematic characteristics of the instrument. The analytical model of the fracture process of rock cutting by tool vibration with considering of plastic properties of the massif were developed. The main technological parameters of massif vibrating cutting with normal variations were modeled: dependences of normal and tangential pressure in the zone of working body interaction with the medium, normal and shear stresses in the zone of destruction, rock characteristics of the medium, vibration parameters dependences on the characteristics of mechatronic system geometry of the contact area of flat incisors treated with medium. The choice of the computational model of the vibration rock cutting with the normal to the direction of movement of the working body fluctuations with considering arising from processes at once or disorders: the occurrence of compressive and tensile stresses were backgrounded. Main stages and interconnection options in the simulation of vibration cutting were established. Scientific novelty lies in the development of a method of analysis of contact interaction of roller working body molding machine with an array taking into account the changes in the stabilization process of physical and mechanical properties of the treated medium, the aim of which is to predict the required voltage and depth of the formed layer. The theoretical basis of rock cutting by flat auger tool taking into account the normal component of the vibration with respect to the movement direction allowing for the deformation of the rock mass and the contact interaction with the working body were established, that allows to improve the technology of drilling wells by reducing the power consumption of the cutting process. The results enable us to determine the parameters of power and kinematic conditions for the occurrence of the vibration cutting.
PL
W artykule przedstawiono tematykę związaną z często pomijanym wpływem kierunku urabiania na generowane opory urabiania skał. Na etapie prac związanych z rozpoznaniem złoża lub doborem sposobu eksploatacji przeprowadzane są badania określające własności mechaniczne calizny. Najczęściej przeprowadza się badania wytrzymałości na jednoosiowe ściskanie oraz czasami urabialności skał. Bardzo często wyniki tych badań silnie zależą od kierunku ich realizacji. Ponadto w zależności od sposobu urabiania (frezowanie, struganie, wiercenie) oraz miejsca pobierania próbek (ocios ściany, czoło lub ocios chodnika) kierunek skrawania zazwyczaj nie jest zgodny z kierunkiem realizacji badań. W artykule zwrócono uwagę na występujące w praktyce kierunki skrawania oraz przedstawiono, opracowane w tym celu dla górnictwa podziemnego, zalecenia dotyczące kierunku prowadzenia badań w celu prawidłowego określenia własności calizny. Zaprezentowano również autorskie wyniki badań węgla kamiennego, soli kamiennej oraz piaskowców, łupków i dolomitów, przeprowadzonych w trzech prostopadłych kierunkach. Ponadto dokonano przeglądu literatury w tym aspekcie, prezentując wybrane badania. Wyniki badań potwierdzają występowanie kilkukrotnych, czasami prawie pięciokrotnych, różnic wartości własności mechanicznych w zależności od kierunku obciążania. Wiedza dotycząca planowanego kierunku skrawania oraz kierunku realizacji badań jest warunkiem koniecznym prawidłowej interpretacji wyników i doboru techniki urabiania, rodzaju narzędzi, parametrów procesu oraz spodziewanej efektywności i energochłonności.
EN
The paper is concerned with the influence of cutting direction on rock cutting resistance, which is a frequently neglected issue. Investigations into the mechanical properties of unmined rock are carried out at the stage of works involving deposit identification or mining method selection. The most frequently performed tests include uniaxial compressive strength and, sometimes, mineability of the unmined rock. The results of these tests are strongly correlated with the direction in which they have been carried out. Additionally, depending on the method of mining (cutting, planning, drilling) and the site of sampling (sidewall, face), the direction of cutting is usually inconsistent with the direction of testing. In the article, the author has drawn attention to the commonly applied directions of cutting and presented recommendations on the direction of testing to be followed in underground mining plants in order to properly determine the unmined rock properties. The results of author’s research into hard coal mine, rock salt and sandstones, shales and dolomites, conducted in three perpendicular directions have also been quoted. Furthermore, the subject literature in this field has been reviewed and selected investigations presented. The research results confirm that depending on the cutting direction, there may be considerable, even fivefold differences in the value of mechanical properties. Knowing the planned cutting direction and the direction of testing is a necessary condition for interpreting the results in a proper way, choosing a suitable mining technique, the type of tools and process parameters, as well as achieving the projected efficiency and energy consumption.
PL
Przedstawiono wyniki badań wpływu najważniejszych parametrów procesu przecinania wysokociśnieniową strugą wodno-ścierną stali Hardox na chropowatość powstałej powierzchni. W celu określenia najkorzystniejszych parametrów kontrolnych procesu skrawania stworzono matematyczno-statystyczny model procesu cięcia wykorzystując metodę powierzchni odpowiedzi (RSM). Wybrano równanie wielomianowe drugiego stopnia i na jego podstawie stworzono model obróbki, umożliwiający znalezienie optymalnych parametrów kontrolnych oraz predykcję wartości chropowatości powierzchni przeciętej.
EN
The results of investigations of the influence of the most important parameters of the cutting process of highpressure water jet cutting of Hardox steel on the roughness of the resulting surface are presented. A mathematical-statistical model of the cutting process based on the response surface method (RSM) was created to determine the most favorable control parameters of the cutting process. A second-degree polynomial equation was chosen and a machining model was created based on this equation to find the optimal control parameters and predict the value of the cut surface roughness.
PL
Współczesną tendencją w obróbce skrawaniem metali jest dążenie do eliminacji szkodliwego dla środowiska chłodzenia zalewowego. Jednym ze stosowanych rozwiązań jest chłodzenie kriogeniczne ciekłym dwutlenkiem węgla (LCO2). Efektywność takiego chłodzenia można podnieść dzięki połączeniu go ze smarem stałym.
16
Content available remote Tekstura powierzchni przyłożenia tłumiąca drgania samowzbudne przy skrawaniu
PL
Znane jest zjawisko stabilności obróbki skrawaniem przy niskich prędkościach skrawania wynikające z przenikania się powierzchni przyłożenia z powierzchnią skrawania, gdy narzędzie przemieszcza się w głąb przedmiotu. W artykule przedstawiono projekt tekstury powierzchni przyłożenia, która tłumi drgania samowzbudne także przy wyższych prędkościach.
EN
The submitted paper deals with the issue of change in structure, hardness and thermally affected zone of the samples of a toothed wheel part produced by technology of cutting by plasma, laser and water jet. The cutting process by laser and plasma technology causes intensive thermal affection of material and change in structure and microhardness in the cutting area referred to as thermally affected zone. The paper describes three material cutting technologies of the toothed wheel part. The experimental part contains description of experimental sample preparation, its hardness measurement and examination of structure along with further evaluation through graphs and photo documentation of structures.
EN
The article describes how different friction coefficients under certain cutting conditions and parameters affect the formation of the stress-strain and thermal states of the product when titanium alloy machining. A new research methodology is used for the study. Firstly, in the initial data for simulation, each time a different declared coefficient of friction is proposed, and every such task of the cutting process modelling is solved for various cutting parameters. The second stage analyzes how these coefficients influence the stress-strain and thermodynamic state of the workpiece and tool during cutting, as well as the tool wear dynamics. In the third stage of the study, ways for ensuring these analytically-grounded tribological cutting conditions are proposed. The analysis of different wear criteria in the simulation models of titanium alloys cutting is carried out. Experimental studies confirm simulation results.
PL
Zaproponowano sposób obliczeniowego oszacowania wpływu zużycia narzędzi skrawających na intensywność zużywania korozyjnego warstwy wierzchniej materiału obrabianego. Cechą charakterystyczną podejścia jest ocena stopnia zużycia korozyjnego w zależności od zużycia narzędzia, parametrów chropowatości powierzchni przedmiotu obrabianego i stopnia utwardzania warstwy wierzchniej na zimno, a także parametrów warunków obróbki technologicznej (parametrów skrawania, geometrii narzędzia skrawającego, właściwości obrabianego materiału i narzędzia).
EN
A possible variant for calculated estimation of the degree of the impact of the cutting tool wear on the value of the part’s surface layer wear obtained during processing with the edge tool, due to atmospheric corrosion, is presented. The feature is the evaluation of the wear rate and its numerical value depending on the tool wear, roughness parameters of the work piece surface, and the degree of cold hardening of the surface layer, as well as parameters of the technological machining conditions (cutting conditions, geometry of the tool cutting part, properties of the machined and the tool materials).
PL
Przedstawiono wyniki optymalizacji parametrów laserowego cięcia materiałów obuwniczych, tj. prędkości oraz mocy. Testom poddano wybrane materiały zróżnicowane surowcem i/lub sposobem wytwarzania, grubością, a także docelowym przeznaczeniem. Na podstawie przeprowadzonych testów stwierdzono, że właściwości fizyczne promieniowania lasera CO2 – Maximus PRO (model: JSM 90 x 60), pozwalają zapewnić wysoką jakość obróbki dowolnych materiałów obuwniczych. Efekty wizualne cięcia zależą od precyzji ustawień ogniskowej pomiędzy płaską powierzchnią cięcia i głowicą lasera oraz parametrów prędkości i mocy lasera. Konieczny jest więc ich każdorazowy dobór na podstawie przeprowadzonych testów kontrolnych.
EN
The results of optimizing laser cutting parameters of footwear materials, i.e. speed and power, are presented. Selected materials were tested, differing in terms of raw material and/or manufacturing method, thickness and intended use. On the basis of the tests, it was found that the physical properties of CO2 laser radiation – Maximus PRO (model: JSM 90 x 60), ensure high quality processing of any footwear materials. The visual effects of the cut depend on the precision of the focal length settings between the flat cutting surface and the laser head, as well as the speed and laser power parameters. Therefore, it is necessary to always select them on the basis of the control tests.
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