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Study of the influence of process parameters on welding properties of ferritic stainless steel and carbon steel in laser oscillation welding
Hála, Kamil ; Sigmund, Marian (referee) ; Mrňa, Libor (advisor)
The Master thesis is focused on the influence of procedural parameters on the properties of heterogeneous weld in laser welding. The literature review section offers an overview of the industrial application of the laser welding technology as well as it explains the issue of heterogeneous weld creation. The experimental part of the thesis aims to describe how six carbon steel samples have been welded together with ferritic stainless steel by usage of several different beam oscillation configurations. Tested samples have been used to create trial ensembles that were subjected for a tension testing, Vickers hardness testing, metallographic testing and corrosive resistant testing. As a result of the experiment, there is a suggestion of the study that could be used for an industrial using of a combination of these materials.
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Weldability of cobalt alloys by hybrid method Laser-TIG
Herčík, Tomáš ; Mrňa, Libor (referee) ; Sigmund, Marian (advisor)
The master thesis summarizes the critical situation of the lack of a cobalt used in different industry branches. Due to its increasing price, it will not be possible to use in existing applications. One of these applications is production of cobalt alloys where the replacement of this element is impossible. This type of material keeps mechanical properties at high temperature. However, a suitable choice of technology can achieve at least its savings. In the field of welding, the alloys are joined without any use of an additional material. The possible solution could be the use of hybrid technologies or electron beam. Verification of weldability of both methods was realised in experimental parts and evaluated by destructive methods. The investigation was performed on wear resistant alloy Stellite 6B.
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Application of WC grains by brazing
Izák, Josef ; Kubíček, Jaroslav (referee) ; Sigmund, Marian (advisor)
Bachelor thesis is aimed to assessment condition of brazing component barking plate. Solder contains grains of tungsten carbide is applied on steel due to raise hardness of plate. Applied solder with grains, does not only raise the hardness, but also multiply increase lifetime of plate. Technology, which is used to brazing, is oxy – acetylene flame. It will be examined two type of solder. In the first it is provided optical exam and then destruction exams (micro hardness, macrostructure, microstructure, SEM and EDS analysis). In the end It was proposed qualifications of brazer and exams of brazing join.
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Friction welding of part chains for forest machines
Houdek, Radim ; Mrňa, Libor (referee) ; Sigmund, Marian (advisor)
The bachelor's thesis is focused on the condition of the weldment of the part of the track, specifically the welding of the cube to the crossbar made of steel 50CrV4 and 27MnCrB5-2. The parts were welded by linear friction welding. The first part of the work is a literature search on the topic of linear friction welding and joined materials. The second part of the work presents the results of a closer examination of weldments. Their macrostructure, microstructure, microhardness were examined in all areas of the welded joint, the amount of residual austenite was determined by X-ray diffraction analysis, the materials were tested for chemical composition and the weldment was tested for breakage.
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Welding of 22MnB5 steel using Laser-TIG hybrid technology
Krejčí, Adam ; Sigmund, Marian (referee) ; Mrňa, Libor (advisor)
This thesis deals with usage of hybrid technology Laser-TIG for welding of boron enhanced steel 22MnB5. This thesis evaluates the influence of preheating using technology of TIG arc welding to a weld quality in comparison with laser welds. In practical part of thesis there were 1,8 mm metal sheets of 22MnB5 welded. This metal sheet specimens were welded by using constant parameters of laser with varying parameters of TIG technology. There were 12 specimens of sheet metal created including 3 specimens using only laser and 9 specimens using Laser-TIG hybrid technology while varying magnitude of current (I=20 A, 40 A a 60 A). Welds created this way were evaluated by tensile test and strength limits compared. Then metalografic survey was carried out examining macro and microstructure. Results of metalografic survey were confronted with Vickers hardness test.
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Plasma overlay welding of cobalt alloy
Paleta, Petr ; Daněk, Ladislav (referee) ; Sigmund, Marian (advisor)
The thesis deals with plasma overlay welding of cobalt alloys. In the theoretical part of the thesis, suitable cobalt alloys for plasma overlay welding were described, out of which cobalt alloy Stellite 21, was chosen for overlay welding for particular part. Subsequently, the plasma overlay welding machine PPC 250 PTM and the torch PHP 250 S, used in the practical part, were described. In the practical part were debug overlay welding parameters and suggest the suitable overlay welding procedure for particular part.
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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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Welding of deep-drawing steels with a protective layer by means of an oscillating laser beam
Holub, Kamil ; Sigmund, Marian (referee) ; Mrňa, Libor (advisor)
This thesis deals with the topic of procedural parameters influence on the properties of welded joint in zinc-coated deep-drawing steels in laser welding with wobbling. First part of the thesis serves as an overview of laser welding technology, welding of steel with protective zinc layer and weld quality testing. Second part is dedicated to a proposal, process flow and evaluation of an experiment. Seven trial lap welding joints of DC04+ZE steel have been welded using different welding parameters. Specimens from these trial welds were used for metallurgical testing by macro-etch examination and for tensile strength break testing to get mechanical properties of welded joints.
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Welding parameters optimalization of robotic welding for car industry
Soprunenko, Valeriia ; Mrňa, Libor (referee) ; Sigmund, Marian (advisor)
Thesis deals with individual technology of new welding processes "specifically FRONIUS TPSi". The greatest emphasis is on welding technology, especially on the differences between the individual methods. The experimental part of the thesis is focused on finding suitable parameters for welding filled welds.Everythingwith respect to required welds quality welded by robotic welding. The samples were evaluated in terms of penetration depth, amount of heat introduced and the number of defects.
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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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