The designed aircraft frame structure uses a connection of tubular rods by welding. To apply automatic welding of trusses, the authors designed and assembled the welding station adapted to the dimensions and truss shape. You should also choose the appropriate welding power source and an interface for communication with a robot or automaton. Automatic welding of trusses also requires programming of the robot’s movement trajectory, especially the welding head, and a particularly accurate selection of welding process parameters. The most important issue of automation of the welding process is the nodes of the aircraft engine frame, whose limited access requires manual welding. Therefore, the future of welding lattice aircraft structures requires a hybrid approach to the process, i.e. some of the node connections can be easily automated, and some will remain in classical manufacturing methods. In addition, the topic of checking such connections using NDT methods was discussed. In addition, the issue of checking this type of connection using methods approved for aviation, i.e. NDT, was discussed.
PL
W projektowanej konstrukcji ramy samolotu zastosowano połączenie prętów rurowych poprzez spawanie. Aby zastosować spawanie automatyczne kratownic, autorzy zaprojektowali i zmontowali stanowisko spawalnicze dostosowane do wymiarów i kształtu kratownicy. Należy również dobrać odpowiednie źródło zasilania spawania i interfejs do komunikacji z robotem lub automatem. Spawanie automatyczne kratownic wymaga programowania trajektorii ruchu robota, zwłaszcza głowicy spawającej, oraz bardzo dokładnego doboru parametrów procesu. Najistotniejszą kwestią automatyzacji procesu jest spawanie węzłów ramy silnika samolotu, które ze względu na ograniczony dostęp wymagają spawania ręcznego. Zatem przyszłość spawania kratowych konstrukcji lotniczych wymaga hybrydowego podejścia do procesu - czyli częściowo proces łączenia węzłów można będzie prosto zautomatyzować, a częściowo trzeba będzie pozostać przy klasycznych metodach wytwarzania. Ponadto podjęto tematykę kontroli tego typu połączeń metodami dopuszczonymi dla lotnictwa, tj. NDT.
W artykule poruszono zagadnienie wpływu pożaru na zmiany w strukturze i właściwościach mechanicznych złączy spawanych elementów ze stali niestopowych. Analizie poddano procesy zachodzące podczas spawania, mające wpływ na uzyskiwaną wejściową strukturę i właściwości w spoinie i strefie wpływu ciepła. Na tej bazie dokonano zwięzłej analizy wpływu niskotemperaturowego i wysokotemperaturowego pożaru oraz sposobu jego gaszenia na zmiany w strukturze i właściwościach mechanicznych złączy spawanych stali niestopowych. Zarekomendowano prowadzenie ekspertyz popożarowych stalowych konstrukcji spawanych.
EN
In the article deals with the issue of the impact of fire on changes in the structure and mechanical properties of welded joints of non-alloy steel elements. The processes occurring during welding, affecting the obtained input structure and properties in the weld and in the heat affected zone, were analyzed. On this basis, a concise analysis of the impact of low- and high-temperature fire and the method of extinguishing it on changes in the structure and mechanical properties of welded joints of non-alloyed steels was made. Recommendations for conducting post-fire expertise of welded steel structures are included.
The article refers to an earlier publication regarding "reinforcing" overlays on welded joints. In this context, the main principles of designing welded structures were reminded. To verify the principle of not using overlays on the welds, an FEM simulation of such a model was performed. Simulation proved that weld overlays used in plate girder structures are ballast, because they do not participate in stress transfer when tensile is dominant. In addition, they generate a stress concentration in the corner of the pad, which greatly reduces the time to fatigue failure of the structure. A list of the recommendations, requirements for the correct use of overlays on welded joints is given.
In the structure of crane bumpers, there is a need to join various types of steel. Usually, low-alloy steel structures are used for this purpose, which can be represented by S355J2 steel. The tensile strength of S355J2 low-alloy steel is slightly below 600 MPa, and the tensile strength of S355J2 steel is at the high level of 200 J at ambient temperature. The impact strength of this steel in negative temperatures is also good at over 47 J at -60 °C, so it meets the 6th class of impact toughness. Welding structures, after classic gas metal arc welding (GMAW) processes, meet only the second impact toughness class. An improved GMAW process was used by micro-jet cooling application to raise the mechanical properties of the joints. The microstructure and main properties of the joints were carefully analyzed. The influence of using the new suggested welding process on the various properties of the welds is presented (UTS - ultimate tensile strength, YS - yield strength, Poisson ratio, elongation, Young’s modulus). Then, the effects of tests for use in crane bumper construction were checked by using a hybrid finite element method (FEM) analysis.
Due to difficult pandemic situation with COVID-19 decease, as well as due to current geopolitical circumstances in the world, we are facing the shortage of steel and therefore the impossibility of delivering the contracted products within the agreed deadlines. It is thus necessary to find suitable steel for replacement. The procedure for selecting one such steel for substituting the deficit steel 25CrMo4,for the purposes of producing a responsible welded assembly, is described in this paper. After the careful analysis, the steel 42CrMo4 was taken into consideration as a possible substitute material. Prior to applying the new selected steel, it was necessary to perform the following tests: analyze its chemical composition, determine its most important mechanical properties and evaluate its weld ability. Then, the optimal welding and heat treatment technologies were determined, so that the quality of the responsible welded structure would meet all the requirements, as the structure made of originally used steel. For the new steel, all the mentioned and some additional tests were conducted and the appropriate welding technology was prescribed. To verify the selected technology, appropriate tests were conducted on the model welded samples, the results of which are presented in this paper. Based on the analysis of the obtained results, it was concluded that the 25CrMo4 steel can be replaced by the 42CrMo4 steel, however, with the mandatory application of appropriate supplementary measures.
Rozwój przemysłu maszynowego ukierunkowany jest obecnie na wdrażanie rozwiązań pozwalających na produkcję w jak największym stopniu bez omyłkową. Głównym powodem takiego podejścia są coraz większe braki kadrowe. Odpowiedzią na takie działania jest m.in.: zastosowanie przyrządów uwzględniających Poka-Yoke, których konstrukcja wymusza prawidłowe operacje w procesie produkcyjnym, wdrażanie częściowej automatyzacji lub robotyzacji procesów produkcyjnych. W niniejszym artykule opisano niektóre wdrożenia z zakresu procesów spawalniczych na przykładzie ustawiaka spawalniczego oraz szablonu.
EN
The current development of the machinery industry is aimed at implementing solutions that allow production to the greatest extent possible without errors. The main reason for this approach is growing staff shortages. The answer to such actions are, among others: the use of Poka-Yoke devices, whose design forces correct operations in the production process, the implementation of partial automation or robotization of production processes. In this paper there are described some implementations in the field of welding processes, such as a welding adjuster, an instrument and a template.
Purpose: This paper aims to assess a separate influence of heat input and base metal grain size on microstructural evolution in the weld adjacent zone of bainitic steels with 1.5…2.0% Cr, welded or overlayed with consumables with 9% Cr after post-weld heat treatment. Design/methodology/approach: Analysis of the width of decarburised layer on microphotographs of welded or overlayed specimens after tempering at 750°C. Specimens were made by using different welding approaches: single-pass welding, multi-pass welding and overlaying. Findings: It is shown that with an increase of the heat input energy, the width of the resulting decarbonised layer decreases linearly; the increase of the base metal grain size leads to a decrease in the layer width after tempering at 750°C. The microhardness testing showed the average hardness in the decarburised layer of 15Kh2M2FBS steel was 161 HV0.1 (minimum – 154 HV0.1), while the average hardness in the rest of the heat-affected zone was 192 HV0.1. Research limitations/implications: Future research may include comparing the creep rupture strength of the weldments made with different welding parameters or base metal grain size to assess the influence of these factors on creep rupture strength. Practical implications: Results permit to achieve minimisation of the rate of carbon diffusion in the weld-adjacent area of the heat-affected zone by means of variation of welded parameters and base metal grain size. Originality/value: An influence of high-diffusivity paths (grain boundaries) on carbon diffusion in the heat-affected zone of dissimilar weldments was confirmed experimentally; the correlation between base metal grain size/welding parameters and the rate of the diffusion during high temperature exposure was found.
Purpose: This paper aims to analyse the application, importance and impact of heat treatment operations used in ferritic stainless steel welding processes on the properties of the welds obtained. In addition, the article aimed to formulate the main problems that occur during the welding process of ferritic stainless steels, including, in particular, the phenomenon of ferrite grain growth due to thermal processes. Design/methodology/approach: The analysis of the available literature covered issues related to heat treatment processes used in the welding of ferritic stainless steels, taking into account the issue of the growth of the ferrite grain under the influence of heat supplied during welding and the possibility of heat treatment of the obtained welds. The analysis also included determining the possibility of inhibiting the growth of ferrite grains by using elements such as titanium, niobium, and molybdenum, thus improving the strength properties of welds. Findings: Organisation of knowledge in the field of the impact on the mechanical properties of ferritic stainless-steel welds and heat treatment processes used before, during, and after welding. Practical implications: Properly selected parameters of the welding process of ferritic stainless steels, especially the amount of heat input, together with appropriate heat treatment parameters, should improve the mechanical properties of ferritic stainless steels. Originality/value: The analysis of the possibility of a wider application of ferritic stainless steels allowed to draw one of the main conclusions stating that the limited possibilities of using ferritic stainless steels in heavy industry are related to their high susceptibility to ferrite grain growth under the influence of high temperature during welding and, consequently, decreases in strength properties of welding joints made of ferritic stainless steels. Additional heat treatment operations are introduced before, during, or after the sapping process to improve their mechanical properties.
EWM GmbH z Mündersbach jest największym w Niemczech producentem technologii spawania łukowego. EWM stale rozwija nowe, innowacyjne procesy spawalnicze. forceTig® to jedna z takich innowacyjnych metod zautomatyzowanego spawania metodą TIG, cechująca się dużymi prędkościami spawania i wyjątkowo łatwą obsługą.
17-4PH stainless steel finds application in the aerospace industry owing to its good mechanical properties and corrosion resistance. In the literature, this steel is described as good for welding, but research shows that it may be problematic due to the formation of defects. In this study, the welded joints were made by the robotic TIG welding method with various welding speeds (2 and 3 mm/s). The joints were subjected to non-destructive testing and were free from defects. The microstructure was observed by light microscopy and scanning electron microscopy. Changes in the microstructure of the heat affected zone were observed and discussed. Based on the observation of the microstructure and the change in the hardness profile, the heat affected zone was divided into 4 characteristic regions. δ-ferrite and NbC were observed in the martensite matrix. The welded joints were subjected to heat treatment consisting of solution and aging in 550°C for 4 h. The microstructure of the heat affected zone become homogenized as a result of the heat treatment. The content of stable austenite in the welded joint after the heat treatment was about 3%.
The publications increasingly describe the support of production processes in both manufacturing and assembly areas. The support in industry is due, among other things, to the insufficient manpower, the need to improve productivity or to increase reliability of production in terms of errors. This article presents an example of an industrial implementation in the welding area. The main objective of the application of the presented example was to replace a commercial product and to speed up the manufacturing process of an axisymmetric workpiece of the sleeve type. The presented proposal was implemented in a company where welding is the main manufacturing technology.
The most common gas-shielded arc welding method is tungsten inert gas welding, which uses shielding gas to isolate the welded area. Such technique is mostly used in the industrial domain, including steel framework fabrication and installation, plumbing systems, and other building jobs. The welding method and the implementation of a suitable welding joint based on some factors that contribute to the fusion process were studied in the present research. The research investigated the specifications and efficiency of the area to be welded in terms of the thermal effect on the welding joint shape and some significant mechanical property-related factors which that were determined during the welding process. In this paper, aluminum alloy sheets, AA 6061-T6, with a thickness of 3 mm, were used with a 60mm width and 80mm length. These sheets were prepared to be welded using welding currents of 90A, 95A, and 100A, welding speeds of 60mm/min, 80 mm/min, and100 mm/min, and gas flow rates of 8 l/min, 9 l/min, and 10 l/min. The experiments were designed at three distinct levels. These levels were selected to create the L9 orthogonal array. Regression analysis, signal-to-noise ratio evaluation, and analysis of variance were carried out. The created model has enhanced accuracy by predicting the reinforced hardness found in the weld specimens, according to the regression study, which showed R2= 90.09%. In addition, it was discovered that the ideal welding parameters for a welded specimen were 100 A for welding current, 80 mm/min for welding speed, and 9 l/min for gas flow. The present research examined the shape of the thermal distribution of welded parts using the engineering computer program ANSYS. The experimental results clarified the proposed approach, as they showed that the welding current is the most influential factor in the hardness of the weld using the fusion process of 90.95%, followed by the welding speed of 7.48%, while the gas flow rate of 1.52% has the least effect. The authors recommend using qualified welders to ensure optimal performance. It is anticipated that these findings will serve as a foundation for analysis to optimize welding processes and reduce welding defects.
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This study investigated the mechanical and corrosion properties of Friction Stir Welded (FSW) and Tungsten Inert Gas (TIG) welded phosphor bronze (CuSn4) joints. Corrosion tests were conducted on the welded joints, and the percentage of weight loss due to corrosion was measured at different time intervals. Results revealed that the percentage of weight loss due to corrosion of the TIG joint increased with time, whereas the percentage of weight loss due to corrosion of the FSW welded joint remained constant. This could be attributed to recrystallisation that happened in the solid-state welding, which reduced corrosion in the FSW welded joint. In addition, tensile tests were conducted to evaluate the strength of the joints. FSW with a spindle speed of 1300 rpm, weld speed of 0.06mm/sec, plunge depth of 0.25mm, pin profile of pentagon, and flat shoulder profile was found to produce good results. TIG welding with a welding speed of 1.75mm/sec, a gas flow rate of 7.5 cm3/min and an amperage of 120A also produced good results. The tensile strength of FSW was found to be approximately 1.6 times higher than that of TIG welding.
Telecommunication, transport and civil engineering play an important role in new research areas. New antennas based on innovative materials are being developed. At the same time, the methods of antenna mounting with the use of high-strength materials to ensure high structural rigidity with the lowest possible weight are being planned. These materials include AHSS steels with ultimate tensile strength (UTS) up to 1700 MPa and elevated yield point (YS); however, welded joints made of these steels have much worse mechanical properties, compared to the native materials. In this paper, it was planned to test the MAG welding of DOCOL 1400M steel (AHSS group). Directly after welding, a micro-jet joint cooling was applied. It was determined to create thin-walled joints that could be used in the formation of antenna mounts.
Purpose: The novelty and the aim of the article is to check the possibility of welding high 9 strength steels with a mixture containing 7000 ppm of nitrogen. Design/methodology/approach: A new welding material and method have been developed in order to obtain a high-quality joint for automotive industry and for antenna holders and towers. The properties of the joint were checked by NDT (Non Destructive test) tests and the strength and fatigue were tested. Findings: Relations between process parameters and the quality of welds. Research limitations/implications: In the future, it can be suggested to investigate the effect of micro addition of nitrogen in gaseous shielding mixtures of the MIG/MAG welding process. Practical implications: The proposed innovation will not cause problems in the production process. Only the innovate shielding gas with micro additives will be modified without affecting the technological process, management and economic aspects. Social implications: Modifying the welding method will not affect the environment and production management methods. Originality/value: It is to propose a new solution with its scientific justification. The article is addressed to manufacturers of high-strength steel for automotive industry and to manufacturers of antenna components and instrumentation.
Systemy dystrybucji energii elektrycznej oparte na szynoprzewodach znajdują zastosowanie m.in. w obiektach przemysłowych wykorzystujących instalacje elektryczne o różnych mocach. Wymagania dotyczące zasilania są realizowane przy użyciu różnych grup szynoprzewodów. Rodzaj używanych połączeń toru prądowego w szynoprzewodach wpływa na przewodność elektryczną połączeń i określa warunki, w jakich można korzystać z szynoprzewodów. W tym artykule przedstawiono wpływ typu procesu spawania złączy w szynoprzewodach aluminiowych pod kątem ich przewodności elektrycznej.
EN
Electricity distribution systems based on busducts are used, among others, in industrial facilities using electrical installations with different capacities. The power requirements are realised by using different groups of busducts. The type of current path connections used in busducts influences the electrical conductivity of the connections and determines the conditions under which busduckts can be used. In this paper, the influence of the type of welding process for joints in aluminium busducts on their electrical conductivity is analysed.
Stainless steel could be treated as the main material used to construct various means of transport, including mobile platforms and tank trucks. An austenitic steel known as 316L steel (1.4401) has high resistance to atmospheric corrosion, natural waters, water vapor, alkaline solutions, and acids, even at elevated temperatures. This steel is weldable, although it is also prone to various types of welding cracks. Many factors influence the quality and mechanical properties of a joint. The most significant of these is the appropriate selection of welding parameters, which should be determined precisely and separately for each type of sheet, depending on its thickness and geometric features. The aim of the present article is to study the influence of main TIG (Tungsten inert gas) welding parameters on the creation of proper joints used in the construction of mobile truck platforms or tank trucks. The proper selection of parameters enables the production of welds with good functional properties. A novelty of this article is the proposal to weld each layer of a thick joint with different parameters, which has an important influence on the mechanical properties of the joint. It is expected that the new material and technological solution will yield a joint with good corrosion resistance and increased mechanical properties. This is important in the responsible construction of means of transport, using the example of mobile platforms and tank trucks. Different tests verifying the properties of joints, including non-destructive testing, tensile strength tests, and fatigue tests, as well as a hardness probe, were applied.
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Tytan, a dokładniej jego stopy, okazał się doskonałym potencjalnym zamiennikiem stali. Ich łączenie jest możliwe z zastosowaniem wielu znanych technologii spawalniczych, ale w każdym przypadku wymaga szczególnego przygotowania procesu. W cz. I omówiono pokrótce podstawowe grupy stopów tytanu pod kątem specyfiki ich łączenia. Cz. II skupia się na metodach łączenia stopów tytanu, poczynając od najbardziej rozpowszechnionych, takich jak GTA, GMA, wiązką elektronów, a na rzadko stosowanych, takich jak lutozgrzewanie, łączenie wybuchowe i dyfuzyjne kończąc.
EN
Joining of titanium and its alloys is possible with the use of a wide range of welding technologies but in any separate case it needs special care and preparation of the process. The main groups of titanium alloys are briefly described regarding their specific joining requirements. Methods of Ti welding are presented, ranging from most widespread, like GTA, GMA and EBW, to the most unusual, like spot-brazing, detonation and diffusion joining. Guidelines and recommendations concerning the specific requirements of titanium welding with the chosen methods are also included.
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W artykule omówiono rodzaj i skład gazów używanych podczas spawania tytanu, cyrkonu i ich stopów, jak również opisano wpływ poszczególnych gazów na proces spawania i jakość złączy spawanych.
EN
The type and composition of gases used in the welding of titanium, zirconium and their alloys are discussed in the paper. The influence of shielding gases on the welding process and quality of welded joints is also described.
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The article considers the features of additive prototyping with the use of additive material by means of high-energy heating. Mathematical modeling of the process of surfacing of filler metal is performed. A significant influence of the feed and electrical characteristics of the arc on the parameters of the surfacing roller was revealed. Regression equations of influence of parameters of mechanized argon-arc welding on the shape of the seam and parameters of accuracy of the obtained product are determined.
PL
W artykule omówiono cechy prototypowania przyrostowego z wykorzystaniem przyrostu materiału za pomocą nagrzewania wysokoenergetycznego. Przeprowadzane jest matematyczne modelowanie procesu napawania spoiwa. Wykazano istotny wpływ parametrów posuwowych i elektrycznych łuku na parametry walca napawającego. Wyznaczono równania regresji wpływu parametrów zmechanizowanego spawania argonem na kształt spoiny oraz parametry dokładności otrzymanego produktu.
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