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Modernization of welding processes in nuclear power plants
Jochymek, Tomáš ; Slováček, Marek (referee) ; Kubíček, Jaroslav (advisor)
The theses is focused on the use of innovative welding method in the repair of the sealing surface of the valve of the Temelín nuclear power plant. After considering all the options, the use of mechanized manual TIG method was chosen for the implementation. In the experimental part, the design of the repair was made on a test sample, where the cladding was performed with a welding set from EWM. Subsequently, verification was carried out by non-destructive testing, where visual inspection, dimensional inspection and capillary testing were carried out. From the destructive testing, a macrostructure check and a Vickers hardness test were performed. As a result of the evaluation, due to the satisfactory tests and the time saving, the proposed repair technology was found to be suitable for solving the problem.
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Laser preheating during of cobalt alloy cladding
Nevřivý, David ; Slováček, Marek (referee) ; Šebestová, Hana (advisor)
In this work, the possibility of using a laser beam for local preheating in combination with the MIG method in the cladding of Stellite 6 cobalt alloy on X12Cr13 steel was investigated. The surface temperature during heating by the laser beam, the temperature cycles and the cooling rate in the heat afected zone at different beam-arc distances were measured. The patterns were assessed based on the geometry and dilution achieved. The structure was evaluated in terms of macro and microstructure. The microhardness achieved was measured for its distribution throughout the entire clad with a focus on the heat affected zone. The performance parameters of the welding source were varied to evaluate their impact on the resulting dilution and changes in the geometry of the design. To achieve higher process efficiency, the cladding speed was increased and the clads were evaluated in terms of macrostructure and resulting clads geometry.
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Digital commissioning of a robotic production system for resistance welding
Šuba, Marek ; Bražina, Jakub (referee) ; Vetiška, Jan (advisor)
The subject of this diploma thesis is the simulation and digital commissioning of a robotic production system for welding elements such as studs on sheet metal parts. The basis of the work is search of information related to industrial robots, PLC control, tools used for welding, fixtures, manipulators, sensors, safety and protection elements commonly used in such production systems. The second part of the work deals with the given problem and it is a virtual commissioning of the given concept of a robotic production system. This means creating its simulation model in the Process Simulate environment, selecting robots, creating robotic trajectories, collision analysis, creating sensors, signals and optimization. Last part includes the connection of the simulation model with the software S-7PLCSIM Advanced and TIA Portal, the creation of control PLC logic in the form of a program, visualization and verification of their functionality using the above-mentioned connection with the simulation model.
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Unconventional Metals Hardsurfacing Technologies
Krejčí, Vojtěch ; Šárka,, Šimůnková-Houdková (referee) ; Čelko, Ladislav (advisor)
The main objektive of the bachelor thesis is to evolve problems of metalic surface welding and to implement the basic partition of the most expanded used technologies of surface welding. Sometimes we can see the term deposition metalic surface welding too but in practice is used technical term metalic surface welding. The introdution includes the basic acquaintance with problems and the characterization of the proces of surface welding including the summary of its advantages and disadvantages. In other chapters we aim on individual technologies of surface welding, its principle and using in technical practice. Simultaneously is worked out the overview of already unused or minimally used technologies of surface welding. After the presentation of individual technologies follows the section dealing with partition of materials used for surface welding by the basic material as well as surface welding materials at the present technical practice. In the experimental section of thesis follows selected examples of using the presented technologies of surface welding in practice at present.
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Comparison of cladding by the electron beam and plasma process
Rudyk, Martin ; Mrňa, Libor (referee) ; Kubíček, Jaroslav (advisor)
This diploma thesis deals with plasma cladding and electron beam cladding. The theoretical part is divided into several chapters which is focused on description of these methods of cladding process. In the practical part the particular experiment of electron beam cladding (EBC) and plasma cladding (PC) is described. In the conclusion overall results were assessed, both methods were compared each other and possible exploitation in industry was described.
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Repair of crane wheel by welding
Jireš, Daniel ; Kubíček, Jaroslav (referee) ; Daněk, Ladislav (advisor)
Diploma thesis examines the most appropriate solution of filler materials, suitable technology and welding parameters for the renovation of the crane wheel. Five different filler materials were suggested and have been subject of macroscopic examination and measurement of quality - primary the hardness of the weld deposit. Additional materials have been chosen to design a mobile weld system, which does not count with the possibility of preheating the base material. As the most suitable filler material, which satisfy all the requirements that emerged STEIN-MEGAFIL A 740 M.
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Numeric simulation of surfacing turbine rotors pinot pins
Tkaný, Jan ; Mrňa, Libor (referee) ; Daněk, Ladislav (advisor)
The master´s diploma thesis elaborated as the master's degree M-STG Manufacturing Technology solves surfacing problems in the simulations of surfacing turbine rotors pinot pins. The work was seen as a preparatory work before the real surfacing. Topic commissioned by Siemens Industrial Turbomachinery Ltd. For welding plates test has been used the method of SAW and the base material was identical to turbine rotor material, X22CrMoV 12-1. Additional material was Fluxocord 42. Simulations were carried out in programs SYSWELD and Visual - WELD. The output of the simulation software are temperature and stress fields, material structures and creations of the CCT diagrams at the base material, filler material, and mixed area.
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Nickel alloy overlay welding parameters optimalization
Lauš, Lukáš ; Kubíček, Jaroslav (referee) ; Sigmund, Marian (advisor)
The aim of these master's thesis is to choose and optimize parameters of the Venturi tube throat weld cladding. The Venturi tube is made from carbon steel ASME SA-106 Grade C. The weld cladding is performed by plasma transferred arc welding. The throat is weld overlaid with nickel base powder Inconel 625. The overlays are made without oscilation. The main requirement was to find a maximum possible powder feed rate and others welding parameters to develop maximum welding speed and productivity on automat. Visual and penetrant testing on the overlays were performed. Metalographic samples were prepared. On the samples was meassured dilution, overlay thickness and width of the heat affected zone. Results are compared with parameters succesfully used in the cooperating company.
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Anticorrosive protection of steam turbines rotors surface
Špičková, Petra ; Kubíček, Jaroslav (referee) ; Daněk, Ladislav (advisor)
This project was elaborated under the graduate major program 2307 of masters engineering studies. It presents a proposal of anticorrosive protection of steam turbines rotors surface. Based on a literature recherché on automated welding and surfacing under flux, an optimized technology of surfacing of anticorrosive and antierosive layers at output parts of low-pressure sections of rotors will be presented. The optimization of the welding technology will be performed to minimize the possibility of hidden cracks due to application of anticorrosive protective surface and will be evaluated on test samples provided by the company SIEMENS.
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Procedural parameters at Inconel 625 cladding
Hrádek, Jan ; Mrňa, Libor (referee) ; Kubíček, Jaroslav (advisor)
The research is focused on cladding of inconel 625 using the MAG - CMT method. It was found that welding without an oscillation does not create the necessary geometry to establish additional layers. When welding with an oscillation, it was researched that the current between 150 and 200 A appears most appropriate in the synergistic mode for welding inconel 625. The resulting weld bead was made at a current of 190 A with pulse dynamics correction set to -4 and correction of arc length to +10 and welding speed of 315 mm per minute.The weld bead was not ideal mainly due to insufficient height. The improvement of results could be achieved by set oscilation with fluent change in acceleration. Because of the time options and difficulty of programming it was used only constant speed for all experiments.
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