|
|
Low Temperature and Cryogenic Treatment of Casehardened Parts
Bílková, Lenka ; Juliš, Martin (referee) ; Kouřil, Miloslav (advisor)
This work deals with the assessment of the influence of low-temperature treatment on the structure and properties of casehardened surface layer of parts. The objective was to assess whether low-temperature treatment is sufficient, insufficient, or unnecessary for the given purpose. Gears which form a part of Zetor tractors gear boxes were used as samples. Thirteen pairs of frozen and non-frozen samples were used; they were taken from production batches throughout 2007, their hardness was assessed and furthermore, the experiment itself, freezing casehardened and hardened samples to different temperatures reaching as low as -196°C, was carried out. A moderate increase in hardness was registered with the majority of the frozen samples, which proved the effectiveness of the low-temperature treatment.
|
|
|
Surface Treatment Technology of Metallic Materials and its Applications using Electron Beam
Matlák, Jiří ; Dupák, Libor (referee) ; Houdková, Šárka (referee) ; Foret, Rudolf (advisor)
Fast deflection is one of the great advantages of an electron beam, making it possible to process a relatively large area at once and also to modify the distribution of the supplied energy. The dissertation deals with surface heat treatment with a focus on the effect of beam deflection on the process. Furthermore, the influence of processing speed and defocusing of the electron beam is studied. The principles of electron beam technology and the summary of surface heat treatment of various materials are presented in the literary part of the thesis. The experimental part is focused on the influence of process parameters on processing in the solid phase, carried out on steel 42CrMo4, and in in the liquid phase, carried out on alloy NiCrBSi. Especially changes in structure, hardness, shape of the processed area and wear resistance are evaluated on processed samples. The results are also evaluated from an energy perspective. Furthermore, an optimum combination of technological parameters is recommended for solid and liquid phase surface heat treatment.
|
|
|
The Influence of Heat Treatment on the Structure and Mechanical Properties of Tool Steels
Tobolík, Stanislav ; Němec, Karel (referee) ; Molliková, Eva (advisor)
This bachelor thesis deals with the properties of tool steels after heat treatment. The theoretical part describes the properties of iron and its alloys with carbon, and an overview of the use of steel. It is also discussed in detail the heat treatment of tool steels and manufacturing process analysis and metallographic sample. In the last part of the bachelor thesis there are described the mechanical testing of metals. In the practical part it is tested structure and mechanical properties of the selected tool steels for two types of heat treatment and the results are compared with the requirements imposed on it.
|
|
|
Heat treatement of gear steels
Šnevajs, Matěj ; Řehořek, Lukáš (referee) ; Jan, Vít (advisor)
This bachelor thesis deals with suitable types of heat and heat-chemical treating of case hardening steel for production of gear wheels. The experimental part focuses on examination of two specific gear wheels made of 14 224 and ZF1A steel, which were donated by the company TATRA TRUCKS a.s. This bachelor thesis presents results of their hardenability, microstructure, hardness and microhardness of the case hardening layer.
|
|
|
Heat treatment of formed parts
Leška, Radim ; Jopek, Miroslav (referee) ; Lidmila, Zdeněk (advisor)
In the research part, the bachelor thesis deals with forming, the mechanism of plastic deformation and steels used for forming. It also describes the principles of heat treatment, specifically the methods used in the preparation of semi-finished products, pressings, and forgings, i.e., annealing, hardening, and tempering. In the practical part, several experiments were performed on C45 steel. The first of them verified the effect of strain hardening after compaction, the others were focused on recrystallization, full annealing, hardening, and tempering. The effect of deformation and heat treatment was assessed in terms of hardness, which was measured by the Vickers hardness test.
|
|
|
Optimalisation of heat treeatment of steel - 27MnCrB5-2
Černín, Jiří ; Němec, Karel (referee) ; Věchet, Stanislav (advisor)
This bachelor’s thesis deal with heat treatment of bor steel, 27MnCrB5-2. The work contains assessment and further proposal of new suitable form fot heat treatment. With request for the most possible hardness and preservation optimal scale of tenacity and reasonable price. Teoretical part describes basic information about heat treatment. In the practical part was investigate sttructure, hardness and chemical composition of six samples.
|
|
|
Heat processing principle of operation thermal resistance annealing.
Špičková, Petra ; Humár, Anton (referee) ; Kalivoda, Milan (advisor)
The project assigned for the bachelors study program B 2307 analyses the theory of heat processing in general and furthermore resistance annealing with the focus on the technology developed by the company Heatmasters. Examples of processing methods used at other technology providers are presented, inclu-ding documentation and datasheets. Resistance annealing is based on the heat transfer from a resistive wire, which heats up by electrical current. The thermal energy is then transferred to the target material through heat radiation or con-ductance. The resistance heat processing is used both for welding and for an-nealing. Nowadays is the documentation and recording of the heat processing of significant importance. Possibilities exist that allow recording of temperature during the entire cycle of the heat processing and subsequently providing the result evidence in a form of a certificate.
|
|
|
Heat treatment of formed parts
Leška, Radim ; Jopek, Miroslav (referee) ; Lidmila, Zdeněk (advisor)
In the research part, the bachelor thesis deals with forming, the mechanism of plastic deformation and steels used for forming. It also describes the principles of heat treatment, specifically the methods used in the preparation of semi-finished products, pressings, and forgings, i.e., annealing, hardening, and tempering. In the practical part, several experiments were performed on C45 steel. The first of them verified the effect of strain hardening after compaction, the others were focused on recrystallization, full annealing, hardening, and tempering. The effect of deformation and heat treatment was assessed in terms of hardness, which was measured by the Vickers hardness test.
|
|
|
Influence of thermal processing to microstructure of various steels
Kocman, Lukáš ; Havlík, Petr (referee) ; Štěpánek, Roman (advisor)
This bachelor thesis deals with the heat treatment of steel, especially measuring the influence of individual heat treatment technologies on changes in the microstructure of steels. The theoretical part of the work presents alloys of iron and carbon, furthermore describes their phase transformations in the solid state, particularly the transformation diagrams of steels. In another part of theoretical part, the basic heat treatment technologies and their influence on the mechanical properties and microstructure of steels are described. The experimental part deals with the preparation of metallographic samples and presents results of examining the microstructure and measuring the hardness of individual samples. At the end of the work the synthesis of the theoretical part and results of the experimental part is used for the partial and overall evaluation of the influence of heat treatment on the microstructure of steels.
|
|
|
Machining of hardened parts
Havlík, Daniel ; Osička, Karel (referee) ; Polzer, Aleš (advisor)
This bachelor thesis is focused on the machining of hardened parts. The beginning of the work is devoted to the analysis of specific materials, 42CrMo4, 42CrMoS4 and 50CrMo4. Next described thing is heat treatment. The main part of this work consists of theoretical analysis turning of hardened parts and theoretical analysis of the thread whirling of ball screw, where the principle of ball screws is also described.
|
guest ::
