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Welding of the framework from aluminium alloys
Rašek, Ondřej ; Daněk, Ladislav (referee) ; Kubíček, Jaroslav (advisor)
For TIG welding of transformer fame is important enough weld root fusion, however exposed surfaces must remain unaffected. Three types of test were made to determine properties of welds under different conditions. Tests were macroscopic inspection, tensile test and fracture test. Next was economic evaluation of different methods. Best results were for single layer weld with pre-heated material.
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Study on dependency of the weld geometry on process parameters in laser hybrid welding of aluminum alloy
Wojnar, Michal ; Kubíček, Jaroslav (referee) ; Mrňa, Libor (advisor)
A study carried out in the bachelor 's degree in engineering technology deals with changes the geometry of the weld technologies created laserTIG . The theoretical part provides an overview of the basic characteristics and advantages of welding technology laserTIG a summary of the issues welding of aluminum alloys. The experimental part consists in the execution of fifteen test welds on a sheet of Al alloy 2024 tl . 3 mm. From the measured values of individual welds were prepared according to the depth and width of the seam TIG welding current at a constant laser power and dependence on a specific area of the weld heat input Qs. By comparing the dependencies have been demonstrated theoretical advantages of laser hybrid technology , which consist mainly of increasing the welding speed and lower heat load of the welded material. Using the laser hybrid welding for welding of aluminum alloys proven advantageous.
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Use of the preheating by electric arc during laser welding of steels with higher carbon content
Mach, Martin ; Sigmund, Marian (referee) ; Mrňa, Libor (advisor)
The thesis is focused on the study of the use of electric arc preheating, in this case source WIG, during laser welding of steel with a higher carbon content, specifically for this work steel 1.1191 thickness 2 mm. Based on the calculation of the carbon equivalent, the preheating was determined to 208 °C. The welding parameters were selected on the basis of the first experiments. In the experimental section, the samples were welded with laser with preheating using a source WIG, which were then made to a tensile test, Vickers microhardness, macrostructure and microstructure. By using a second heat source, the heat-affected area of the samples was expanded. Samples that cracked in the middle of the weld during the tensile test were heat influenced by cutting samples. The remaining samples was broken in the base material, thus the weld produced was of good quality. Combination of laser welding with WIG electric arc preheating is a very productive method over conventional methods and one of the few pre-heating solutions for laser welding. These are the initial experiments for the use of the WIG arc for preheating in laser welding, to be followed by further research, mainly for the automotive industry.
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Certification of company according to ČSN EN 15085 and ČSN EN ISO 3834
Kazdera, Tomáš ; Daněk, Ladislav (referee) ; Kubíček, Jaroslav (advisor)
The project elaborated in frame of engineering studies is focused on the certification of the company SW-MOTECH sro in the welding of steel structures for rail vehicles. According to standards ČSN EN 15085 and ČSN EN ISO 3834. The first part focuses on theoretical introduction to the used welding methods. The second section describes the destructive and non-destructive tests on individual welding methods, including their evaluation. Based on work tests pWPS is exposed to welding procedure WPS
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Study weld porosity aluminum alloy 5000 series during hybrid welding Laser-TIG
Drápela, Petr ; Kubíček, Jaroslav (referee) ; Mrňa, Libor (advisor)
This bachelor thesis is aimed on studying weld porosity of aluminium alloys made by laser-TIG technology. Theoretical part deals with welding methods and their parameters, capabilities and usage. Methods are investigated separately then as a unit. At the end of the theoretical part there is summary about welding aluminium alloys and their properties. In experimental part it is made eleven testing welds on sheet metal from aluminium alloy EN AW-5754 H111, thickness 5 mm. After this sizes of welds are measured. From these sizes dependences welding current to input heat Q are made. Final part concerns analysis of welding defects and final evaluation optimum welding parameters.
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Welding technology of the "fuel cell" component
Vaculka, Jakub ; Dohnal, Ivo (referee) ; Kubíček, Jaroslav (advisor)
The project aimed at the selection of the optimal welding method for a „fuel cell“ component in terms of the VN-Ú Ltd engineering company. The goal is to compare the methods available in VN-Ú, that is: TIG, MIG/MAG and CMT. It is necessary to analyze the specifics of each of the technologies and the operation conditions which the component will be exposed to. For the comparison of the methods, non-destructive testing of the components, as well as destructive tests of the produced samples have been used. The economic evaluation has been used to compare the costs of different welding methods of the components and to assess the potential investments in CMT device that has only been leased by VN-U so far.
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Possible design and performance mistakes of welds for resulting chemical threatment by pickling
Hendrych, Marek ; Kubíček, Jaroslav (referee) ; Sigmund, Marian (advisor)
The diploma thesis deals with the issue of surface treatment by pickling. In the research part the pickling technology is described in detail. The next chapters are focused on the TIG welding method and the weldability of austenitic stainless steels. In the experimental part an experiment is carried out focusing on the comparison of weight loss and surface quality depending on the pickling time. Part of the conclusion is the implementation of pWPS documentation for the specified component and a brief manual for customers of pickling plant.
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Orbital welding in terms of nuclear power plant Temelin
Toman, Petr ; Šnajdárek, Ladislav (referee) ; Fiedler, Jan (advisor)
The bachelor thesis deals with the selection of a suitable system for Orbital welding of impulse pipe at the Temelín Nuclear Power Plant. The aim of this work is to describe the current TIG method of manual welding, to describe the available Orbital welding technology, to select a suitable type of kit and to design an experiment to compare the products of individual manufacturers.
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The problems of welding stainless steel 1.4541
Šmarda, Vladimír ; Sigmund, Marian (referee) ; Kubíček, Jaroslav (advisor)
This thesis focuses on austenitic steel welding in the upper part of a steam generator at the nuclear power station Dukovany, and the suitable technology when replacing this part. Part of this thesis is dedicated to the progressive methods TIG, such as the use of hot wire or orbital welding of pipe parts. The experiment in this thesis project tests the optimal parameters setup when welding while using a modified TIG method; a motor-fed hot wire with a welding source from EWM manufacturer was used in this project. Number of NDT tests, along with destructive tests including metallographic tests, demonstrated and verified that the methods, the additional materials and the way the experiment was carried out were chosen correctly and proved effective. These tests also included the hardness of the welding point and TOO locations. The experiment assessment part summarizes the experiment execution, describes the results of the tests, and recommends further continuation in the process toward WPQR
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Preparation and welding of the pressure aluminium pipes
Kocák, Tibor ; Sigmund, Marian (referee) ; Kubíček, Jaroslav (advisor)
The project is an analysis of technology production of pressure pipes made of aluminum alloys. The basis is a literary study of TIG technology, aluminum heat-tretable and non-heat-treatable materials. The flange-material is EN AW 5083 and the pipe is made of EN AW 6005A. The design of the welding is compromise between the preparation, the cleaning of the welding edges and the weld metal backing strip. Weld was made in real production. Examined impacts are evaluated on the basis of destructive and non-destructive welding test methods. After heating process of weldment material exhibits better mechanical properties. Using the economical and technological evaluation were selected sutiable proces parameters. The result is a suitable weld of the pressure vessel. Further optimization is possible through automation and robotics.
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