|
|
Structural analysis of austenitic weld joints
Procházka, Robert ; Foret, Rudolf (referee) ; Havlík, Petr (advisor)
The bachelor thesis deals with structural analysis of austenitic weld joints by using methods of material science. The theoretical part of the thesis summarizes the problematics of welding of high-alloy steels. After the general definition of welding and weldability of high-alloy steels, the thesis focuses on structural adjustments including welding defects during the welding process. Selected methods of fusion welding that were used to create these welds are mentioned in the second half of the theoretical part. The experimental part covers the structural analysis of the welds, which consists of microstructure evaluation, chemical composition analysis, and microhardness test.
|
|
|
Welding of high strenght steel by laser
Číp, Tomáš ; Kubíček, Jaroslav (referee) ; Mrňa, Libor (advisor)
This project, elaborated within the engineering studies (code of field of study: N2301), presents experiment of welding of high-strength steel by laser. In this project, the samples of high-strength steel DOMEX 420MC will be welded by laser welding method and the welded joints will then be compared with welds made by MAG method. The theoretical part of this project summarizes the following key words in individual chapters: lasers, technology of welding of steel using laser, welding by MAG method, steel with higher strength, types of defects and check of welded joints. The practical part contains description of and assessment of mechanical tests of welded joints – weld bending test and transverse tension test. Further on, the tests of macrostructure and microstructure of welded joints were conducted and assessed. Final results of whole experiment are reviewed at the end of my diploma thesis.
|
|
| |
|
|
Laser welding of steels
Křivan, Miloš ; Mrňa, Libor (referee) ; Kubíček, Jaroslav (advisor)
The project elaborated within the bachelor‘s degree field of B-STI Mechanical Engineering is focused on the problems of laser welding of steels. The theoretical part of this project deals with lasers, methods of laser welding, effects of welding parameters on weld quality and the weldability of steels. In the practical part sheets that were made of S355J2G3 and S355J2C+N steels were butt welded. The aim of the practical part was a determination of such welding parameters as the welded joints meeting the quality requirements according to ČSN EN ISO 13919-1 standard and the hardness requirement less than 380 HV10 according to ČSN EN ISO 15614-11 standard. The tests of the macrostructure of the welded joints were conducted and assessed and the hardness of the welded joints was measured.
|
|
|
Design of bearing bracket welding process.
Houdek, Aleš ; Janík, Martin (referee) ; Daněk, Ladislav (advisor)
The thesis deals with a draft production procedure for a specific welded component of a bearing console, including the consideration of the basic material welding quality, the selection of welding method and parameters, thermal processing, if applicable, and the selection of filler material. Draft welding procedure of WPS and weld check. Consideration of the use of a robot.
|
|
|
Welding thin-walled pipes made of stainless steels
Naď, Tomáš ; Sigmund, Marian (referee) ; Kubíček, Jaroslav (advisor)
The bachelor's thesis deals with technology of welding of thin-walled stainless steel pipes and the analysis of weldability of stainless steels. The theoretical part provides a basic description of the material's weldability and the basic defects in welding, the characteristics of stainless steels, their division, marking, alloying and a general overview of their weldability. The experimental part describes selected welding technologies used for the production of thin-walled stainless steel pipes (LBW, PAW, HFIW). Finally, the technology used to weld the presented samples of thin-walled pipes is ascertained and the macrostructure of the weld are compared.
|
|
|
Examination of degradation frequently repaired shearing and forming tools
Izák, Josef ; Kubíček, Jaroslav (referee) ; Sigmund, Marian (advisor)
The diploma thesis is focused on the renovation of forming tools made of tool steel, their weldability and assessment of the quality of tool repairs. The damaged tool was a part of the cutter from the progressive cutting tool made of Caldie steel. We used micro TIG technology to repair the damage. A total of three types of additional materials were used and investigated to restore the geometry of the damaged edge. One of the main purposes was to evaluate the possibility of extending the life of tools and reducing the implementation of already inefficient repairs. A number of destructive tests were performed for the assessment - macrostructure, microstructure, hardness measurement and EDS analysis.
|
|
|
Welding of turbine rotor materials
Palán, Marek ; Vaněk, Mojmír (referee) ; Daněk, Ladislav (advisor)
This thesis deal with the basic problems of welding rotor materials. It describe the essence of welding and ways of detecting defects caused by welding. Furthermore, it is covered in more detail the formation of heterogeneous welds and the impact of individual elements in the weld on the properties of the resulting weld. It lists detailed breakdown of creep-resistant steels and principles of their heat resistance. The thesis gives an overview of welding used in welding rotor materials and various methods are described. The work also includes commissioning of thermal processes in welding. In the experimental part is evaluated macrostructure, hardness and the method used in the implementation of the cladding material 26NiCrMoV14-5.
|
|
|
New materials in welding technology
Křížek, Stanislav ; Janík, Martin (referee) ; Daněk, Ladislav (advisor)
The bechelor work elaborated in frame of studies branch B2339 deals with weldability of new kinds of steel especially about high-strength steel. This is a literary pursuit that includes problems with weldability, that means standing heat deformation cycle on defect activity in welding connection.
|
|
|
The evaluation of the lifetime period of welded frame for hydraulic press machine RONDOPRESS
Čermák, Petr ; Mrňa, Libor (referee) ; Kubíček, Jaroslav (advisor)
Petr Čermák: Service time assessment of the welded frame for the hydraulics of RONDOPRESS press machine The goal of this thesis is to assess durability of the welded frame for the hydraulics of RONDOPRESS press machine, which is used at the bakery sector in the food industry. The press machine chamber is made of stainless steel, because of food (dough) processing. But the strengthened part of the press machine consists of a carbon steel frame with a hydraulic cylinder. For the life of the RONDOPRESS machine is determining the rigidity and durability of the frame. Therefore it is necessary to carry out a study of carbon steel weldability, choose a suitable welding method and then make an evaluation of welded frame construction used in terms of weld joints in analyzed areas. Practical part consists of the frame computer model design, stress calculations and the service time calculation for required 1,825,000 cycles, choosing the appropriate welding method and avoiding undesired deformations. The final output is an operational frame of the RONDOPRESS press machine that meets the required service time specified by the number of production process cycles.
|
guest ::
