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Testing of high-temperature corrosion resistance of 16M03 steel
Šikl, František ; Kolomý, Štěpán (referee) ; Zemčík, Oskar (advisor)
The aim of this work is to design and perform an experiment that simulates the environment of a municipal waste incinerator. However, the whole process of corrosion in real life can take several years, so it is necessary to accelerate these processes in both higher areas and more aggressive environments. The investigated material is 16Mo3 steel. The first part of the work is a search of selected issues of corrosion and materials used in the energy industry. The next part of the work deals with the design of the experiment, which consists of several parts. These may include the appropriate choice of chemical compounds used or the choice of measured temperatures or sample preparation, the experiment being adapted to the available equipment of the BUT FSI workshop. In the last part of the work, testing of the specified material for temperatures of 900 °C, 975 °C and 1 050 °C is performed, while the composition of the mixture is designed as 35 wt. % Na2SO4, 30 wt. % KCl at 35 wt. % NaCl. The measured values are compared depending on the temperature, where, as predicted, a larger graphical dependence can be seen at higher values. At the end, the results of corrosion loss of 16Mo3 steel were compared with Inconel 625 superalloy, where the theory already differs from practice. Furthermore, chemical analyzes from the experiment were performed at 1 050 °C and, based on these obtained values, the proportion of individual elements can be adjusted with the salt mixture used. This adjustment is recommended to reduce the NaCl content due to the higher Na content, as well as to increase the KCl content due to the low K content.
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Dimensional, Shape and Material Analysis of Bimetal Parts with Defined Bending Radius
Ivánek, Radim ; Studený, Zbyněk (referee) ; Sedlák, Josef (advisor)
The thesis aim is an evaluation of achieved results coming from the analysis of pipe bend 180° for the critical bending / bend 1D and supercritical bending / bend 0,7D. The theoretical part is focused on material property of a bimetallic pipe and on methods applied to work out the analysis. The definition of critical points at a considered segment and possible defects arisen while bending is embodied in the thesis. The practical part of the thesis is based on presenting dimensional and proportional analysis based on using optical microscopes and 3D scanner GOM ATOS. The material analysis was aimed at macrostructure as well as microstructure of the bimetallic pipe material, at chemical composition and at the hardness when low-loaded. The analysis achieved results are assessed at the end of the thesis.
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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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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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Analysis of Mechanical Properties of Bimetallic Materials with Clad Layer of Inconel
Sýkora, Milan ; Joska, Zdeněk (referee) ; Sedlák, Josef (advisor)
This diploma thesis deals with the analysis of mechanical properties of bimetallic materials with clad layer of Inconel. In the theoretical part of the work there is an analysis of the investigated bimetallic material. The following is a description of mechanical tests and methods for evaluating the integrity of the surface, which were used to determine the properties of bimetallic material. The experimental part focuses on individual tests of mechanical properties of the material. For each test, the procedure for the production of test specimens, a description of the test equipment, the performance of the tests, the evaluation of the data obtained and finally, the evaluation of the results obtained are given.
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Influence of asymmetry loading cycle on fatigue crack growth of alloy Inconel 625
Kander, Jan ; Kohout, Jan (referee) ; Věchet, Stanislav (advisor)
The main subject of this bachelor thesis was to evaluate influence of asymmetry of loading cycle on fatigue crack growth rate in a nickel-based superalloy Inconel 625. Experimental part of this thesis was carried out in Material and metallurgical research Ltd. Company in Ostrava, it’s main aim was to study the influences of loading cycles with parameter of asymmetry R = 0,1 and R = 0,7 on crack growth rate. Theoretical part deals with structure of nickel-based superalloys and fatigue crack growth rate.
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Critical Heat Flux on Smooth and Modified Surfaces
Suk, Ladislav ; Kolat, Pavel (referee) ; Katovský, Karel (referee) ; Fiedler, Jan (advisor)
This thesis deals with the problem of critical heat flux (CHF) on technically smooth and treated surfaces at low pressures. The theoretical part presents the basic concepts of two-phase flow and an analysis of existing work on the influence of the surface on CHF. The main part of the work describes the built experimental apparatus for CHF research at low pressures of 100 -1500 kPa (1-15 bar) with a vertical internally heated annular test section. The internal annuli consists of an outer glass tube with an inner diameter of 14.8 mm and an inner tube made of Inconel ™ 625 / Optimized ZIRLO ™ with an outer diameter of 9.14 mm and a heated length of 380/365 mm. CHF experiments on technically smooth surface were performed at outlet pressures 120 kPa, 200 kPa and 300 kPa, at an inlet temperature of 64, 78 and 91 °C and at mass flux of 400, 500, 600 and 800 kg / m2s. The Inconel tubes were tested in two different surface modifications - abraded and bead blasted. Experiments were performed at mass flows of 400, 500 and 600 kg / m2s. The total number of 122 experimental runs were conducted and the results were compared with other literature experimental data. The maximum increase of CHF on abraded / bead blasted tube was 18.12% / 16.17%. The surface structure was analysed by laser microscopy. The wetting behaviour of the surface structures was measured by the sessile drop method. The elemental analysis of the surface was evaluated using the EDS method.
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Testing of high-temperature corrosion resistance of Inconel 625
Tomek, Jiří ; Sliwková, Petra (referee) ; Zemčík, Oskar (advisor)
The aim of the diploma thesis was to design an experiment for testing the high-temperature corrosion resistance of Inconel 625. The experiment was performed at two (900oC and 975oC) on a total of 6 samples (3 for each temperature). The experiment was performed in a dissolved mixture of salts (35% Na 2 SO 4, 30% KCl and 35% NaCl) in a „PEC Lac PK 105/12“ furnace. Based on the results of individual measurements, experimental parameters and future steps were proposed. The diploma thesis also presents a basic description of the project of which it is a part. Where the project originated and what stage it is at. The project was created based on the requirements of BPP Energy s.r.o. to develop a device for bending pipes made of 16Mo3 material with a weldment from Inconel 625. The results of the diploma thesis are also compared with the results of the same measurement, but for 16Mo3 material. In the research part, the diploma thesis deals mainly with the material Inconel 625. Furthermore, the diploma thesis is focused on high-temperature corrosion resistance, therefore the corrosion process is described. And in the completion, attention is paid to the welding process.
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Analysis of Inconel 625 weld layer produced by MIG-CMT
Chrást, Daniel ; Slováček, Marek (referee) ; Kubíček, Jaroslav (advisor)
Návary z materiálu Inconel 625 na základní materiál 16Mo3 slouží v energetickém průmyslu u spaloven odpadu pro zvýšení životnosti membránových stěn. Návarové housenky jsou vytvořeny pomocí metody MIG-CMT. Byly provedeny analýzy makrostruktury a mikrostruktury za použití SEM mikroskopu Apreo 2, dále byla provedena analýza chemické složení návarové housenky za použití OES spektrometru ISpark. Nakonec byly provedeny analýzy vybraných mechanických vlastností, konkrétně mikrotvrdost a tažnost.
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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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