National Repository of Grey Literature 295 records found  previous11 - 20nextend  jump to record: Search took 0.00 seconds. 
Study of the influence of process parameters on welding properties of ferritic stainless steel in laser oscillation welding
Křepela, Petr ; Kubíček, Jaroslav (referee) ; Mrňa, Libor (advisor)
The aim of this work was to carry out an experiment to assess the influence of the individual welding parameters in the laser welding method with the beam wobbling on the made weld, respectively. welds. The material which was welded was ferritic stainless steel with the designation 1.4016, which, like all ferritic steels, is susceptible to coarse grains and the resulting brittleness which leads to degradation of the mechanical properties of the weld. The welds were compared to a sample welded without wobbling an between themselves. Unfortunately, however, the evaluation of the test samples did not bring significant differences from laser welding without wobbling, however some changes are evident, such as grain orientation, weld defects, or uniformity of mechanical properties over the weld length, where wobbling frequency is most important. Further research should focus on limiting the porosity at higher wobbling frequencies in the shape of a circle or ellipse.
Study of the influence of process parameters on welding properties of ferritic stainless steel and carbon steel in laser oscillation welding
Rýznarová, Martina ; Kubíček, Jaroslav (referee) ; Mrňa, Libor (advisor)
In the thesis, the influence of the shape of the beam wobbling geometry and the spot vibration frequency on the properties of the heterogeneous weld of X12Cr13 martensitic stainless steel with carbon steel S355MC in laser oscillation welding is investigated. Macroscopic control was performed on the samples, which were focused on weld size and heat affected areas, weld defects, weld shape and cant / drop face and weld joint root. Subsequent microscopic inspection determined both the weld metal structure and the heat affected area and base material. The last was a Vickers microhardness test. Based on the experiment, it was found that the spot process frequency is an important process parameter.
Study of properties of laser welds of Domex 460 MC material using arc preheating
Novotný, Michal ; Kubíček, Jaroslav (referee) ; Mrňa, Libor (advisor)
This diploma thesis deals with weldability of Domex 460 MC material. There are two welding methods and three other welded materials in heterogenous connection which will be researched in this diploma thesis. The welding methods are fiber solid-state laser and a new method of hybrid welding called laser – TIG. The other materials are Domex 700 MC, S355J2 and DC01. Domex 460 MC is a high-strenght steel with fine-grained structure. During the welding process the imput heat decreases mechanical properties of the materials. This effect is caused by material seeds growing. From these samples (which were produced by welding) were created metallographic cuts. These metallographic cuts were analysed focusing on their makrostructure, microstructure, mikrohardnest and Mn arrangement in welded heterogenous samples using electron microscope and EDX analysis.
Influence of technological process of powder painting on the quality of silver-plated components in gas insulated substation - GIS
Nováková, Eliška ; Prosecký, Vít (referee) ; Kubíček, Jaroslav (advisor)
The thesis deals with the topic of silver coating on the inner surface of the tubes made of aluminum alloy EN AW-6101B. The high affinity of the aluminum for the oxygen, the heterogeneity of the surface and the presence of the hydrogen in the base material, are the properties which hinder the formation of metallic coating on the surface of the aluminum alloy. The saturation of the base material with the hydrogen, e.g. due to the pretreatment of the surface or by the process of creating of coatings, may under certain conditions cause the defects of the silver coating in the form of the bubbles (blisters). Other factors that may affect the quality of the silver coating are the way of creating of the interlayer and the conditions for the electrolytic deposition of the silver.
Influence of shape of the electrode to weld pool
Hrádek, Jan ; Vaněk, Mojmír (referee) ; Kubíček, Jaroslav (advisor)
The project is focused on welding of TIG method. In this method is used non-melting tungsten electrode, which can have different top angles. In different literature there are different opinions about how angle influence weld pool. It was sharpen six different angles of electrode with whom was done welds on carbon steel S235JR and on austenitic corrosion resistant steel x5CrNi1810. The evaluation was done with help of chart where on the axis x is angle of electrode and on axis y are depth and width weld in millimiters. The result of this project was the prove of opinion that with more sharper angle of electrode is depth of weld smaller and width bigger.
Technological process of forging die repair
Kriegsmann, Luděk ; Vaněk, Mojmír (referee) ; Kubíček, Jaroslav (advisor)
The bachelor thesis presents a proposal and solution of renovation of forging insert, which is made of tool steel 1.2367. Due to the literature search, manual electric arc welding with coated electrode was chosen for renovation. The work deals with the stress of the forging insert, which was carried out by strength and thermal analysis. After performance of trial overlay by several coated electrodes, hardness measurement and calculation of dilution of materials was performed. Based on these results, electrode Capilla 66 was selected. Renovation of insert was performed according to preliminary technological process pWPS. The Insert was preheated to 300 °C. As a power source was used TransPocket 3500 and welding current was 190 A.
Welding of steel austenitic
Šmarda, Vladimír ; Mrňa, Libor (referee) ; Kubíček, Jaroslav (advisor)
This thesis deals with welding of austenitic steel, which used in pipelines for liquids in the Dukovany Nuclear Power Station, and suitable technology for welding of joints. Firstly, there is introduced the distinction between the types of stainless steel. Concerning the austenitic steel there are stated their features and defects during welding. Secondly, the bachelor thesis deals with commonly used welding method: MMA, MIG/MAG and TIG, which is most frequently used for weld joints in the Dukovany Nuclear Power Station. A part of the chapter is devoted to progressive TIG methods, such as: use of hot wire and orbital welding of pipelines. In the experimental part, there is solved a proposal for a method and a technique for weld joint between two chambers of tubular cooler. The dimension of the pipeline flange is according to DN 400. It is a butt weld in V-shape with permanent pad on the inside of the pipe, which is welded with TIG method. On the basis of the NDT verification test and also destructive testing, there was proved that the chosen method, technology and additional material were optimal. In the part of experiment evaluation, there were summarized all the results of the tests. Eventually, the suggested weld joint was recommended for realization.
HSS welding process automation in nuclear power plant
Charvátová, Eliška ; Mrňa, Libor (referee) ; Kubíček, Jaroslav (advisor)
The bachelor thesis compares the manual and mechanized method of welding in the production of dissimilar weld joint. The samples were welded from austenitic and ferritic-perlitic parent materials with using the same type of high alloy filler material. Joint geometry is identical for both methods. Nondestructive and destructive controls were performed, the structural changes in the materials given by the different amounts of heat transfer into the weld joint were compared. Increasing the corrosion resistance of the inner pipe surface is ensured by nickel layer.
Chromatographic separation of aflatoxin analogues
Moravcová, Dana ; Planeta, Josef ; Lunerová, K. ; Duša, Filip ; Šesták, Jozef ; Kubíček, J. ; Horká, Marie
Three short particle-packed columns (50 x 2.1 mm) were compared for the rapid and efficient chromatographic separation of aflatoxin G1, G2, B1 and B2 analogues.

National Repository of Grey Literature : 295 records found   previous11 - 20nextend  jump to record:
See also: similar author names
20 KUBÍČEK, Jan
1 Kubíček, J.
20 Kubíček, Jan
9 Kubíček, Jaromír
3 Kubíček, Jaroslav
3 Kubíček, Jindřich
1 Kubíček, Jiří
1 Kubíček, Josef
1 Kubíček, Jovan
20 Kubíček, Ján
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