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Welding of steel C45
Hála, Kamil ; Sigmund, Marian (referee) ; Kubíček, Jaroslav (advisor)
The aim of this bachelor‘s thesis is to propose a suitable welding parameters for a small part of steel C45. This steel contains a high percentage of carbon and therefore is difficult to weld. Gas shielded arc welding techniques were considered to be used, and from such techniques, the TIG method seems to be the most advantageous one. For this technique were suggested three groups of parameters and the most suitable one was chosen to be used for the production. The option chosen is of a welding power I=40 A and with preheating 200 °C. The component is made in the single-part production in SAAB Czech s.r.o.
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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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Comparison of GTAW and Plasma Welding
Hotárek, Jan ; Kubíček, Jaroslav (referee) ; Daněk, Ladislav (advisor)
The work presents a comparison of two welding methods: plasma welding and GTA W. The principle of both welding methods was described in the theoretical part of this work. For the experimental part a base material was chosen - chrome-nickel steel labeled X5CrNi 18-10 and added material in the form of rod OK TIGROD 16.95. Three samples were made for each welding method. Samples were assessed according to applied specific heat which didn't vary in case of the samples made by plasma welding but was different for each sample made by GTA W. Further, the samples were assessed according to a development of hardness: in case of plasma welding the values at the edge of the weld were significantly higher than at the root of the weld but in case of GTA W the values at the edge and at the root of the weld were almost the same. The area affected by heat was not adequately distinctive with any of the samples. The check of the final structure of the welded material was performed with the help of the Shaeffler diagram. For plasma welding method, for which added material in the form of rod was used, dilution of the welding metal was determined.
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Compared HAZ the methods of welding TIG, MAG and CMT
Šoulák, Petr ; Sigmund, Marian (referee) ; Kubíček, Jaroslav (advisor)
The bachelor thesis was to compare the HAZ size for the TIG, MAG and CMT methods. The welded materials were low carbon steel and austenitic stainless steel. Samples of 250x50 mm size and 2 mm thick were welded with butt weld without a gap. In the first part of experiment, samples were welded at the same welding speed. The second part concerned only CMT, where the optimal welding speed was used. For selected samples, the HAZ size was measured and compared in macroscopic images.
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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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Working chamber of electron beam welder
Červinka, Petr ; Mrňa, Libor (referee) ; Daněk, Ladislav (advisor)
The submitted work deals with the design of the working chamber of the electron beam welders. This vacuum chamber of the cubic shape, with a volume of approx. 100 litres will be used in the ÚPT of the AV ČR v.v.i. during building an experimental welding with electron gun performance 2 kW with accelerating voltage 60 kV. The theoretical part is about the theory of electron welding, electron beam welders of basic sections of the facility, and about possibilities of the technology for welding working chambers. In the practical part of the thesis is being thought out the design of the working chamber (construction chamber in design software), the strength test of construction chamber in the software ANSYS and the design of appropriate methods of welding. The sample of the material which is the stainless steel 17240, from which the chamber will be made, have been used in methods of welding TIG and MAG that was verified by the suitability of the chosen methods of welding.
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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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Renovation of tools steels for cold forming
Hrabina, Martin ; Mrňa, Libor (referee) ; Kubíček, Jaroslav (advisor)
Master’s thesis “Revovation of tools steels for cold forming“ characterizes wear resistant welds for tool steels. The thesis is dividend into two main chapters. The first chapter of the thesis is focused on the theory of wear for cold work steels. The theory is combined with an experimental chapter. The experimental part describes particular materials and technology for welding. The conclusion of the thesis is evaluated results of test for mentioned technology and welding conditions.
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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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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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