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Heat treatment of hand tightening tools
Gregor, Martin ; Kouřil, Miloslav (referee) ; Doležal, Pavel (advisor)
Bachelor´s thesis deals with problems of heat treatment of hand tightening tools. Literary analysis is focused on the principles of heat treatment such as annealing, austenitizing, quenching and tempering. Attention is also focused on unconventional heat treatment technology using vacuum and furnace atmospheres based on nitrogen. Analysis of dividing and heat treatment of tool steels is another subject of literary research. In the experimental part are machinery and technological progress of the stock in the company Wera Werk s.r.o., which has more than 50 years engaged in the manufacture, sales and innovation of hand tightening tools. Following processing of the experimental material with a focus on heat treatment and mechanical properties indicate in laboratory tests. Based on the measured and statistically processed values of mechanical quantities is developed design optimization process of heat treatment of hand tightening tools of Wera Werk.
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Influence of the electron beam trajectory on the surface properties of steel 42CrMo4
Mikuš, Tomáš ; Kouřil, Miloslav (referee) ; Foret, Rudolf (advisor)
The thesis deals with surface quenching of steel 42CrMo4 by electron beam. Influence of technologic parameters and beam deflection on properties and structure of prepared layers is studied. Electron beam surface quenching was applicated with and without melting of the surface. Structures of layers made by electron beam quenching were compared with structures made by laser and electromagnetic induction. Structures and phases were analysed by optical microscopy, SEM and roentgen diffraction. Hardness was measured on hardened layers.
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The simulation of steel rod improvement by the induction lines heat treatment
Chmiel, David ; Turoň, Rostislav (referee) ; Kouřil, Miloslav (advisor)
Bachelor thesis deals with possibilities of simulation of induction heat treatment. Literary analysis is focused on the method of induction treatment, the physical nature and its use for the heat treatment. For completeness is in the end comparison of different methods of heat treatment. The experimental part describes the future of quenching and tempering of steel bars in company Třinecké železárny a.s. Also is contained method of simulation of the heat treatment in computer program QTSteel and the subsequent design of parameters for a continuous processing.
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Surface treatment of selected steels using electron beam
Matlák, Jiří ; Jan, Vít (referee) ; Kouřil, Miloslav (advisor)
The aim of diploma thesis was preparation of hardened layer on three chosen types of materials with different alloying components content without surface melt by using electron beam technology. The influence of chosen process parameters was observed on the prepared hardened layers properties and shapes. In the first part of bibliographic search there are described electron beam properties, possibilities of his influencing and control. There is given example of complete set of electron beam are mentioned in the second part of theoretical research.
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determination of kinetic parameter of reactions using DSC
Kopecký, Jan ; Kouřil, Miloslav (referee) ; Jan, Vít (advisor)
The master thesis deals with DSC measurments a calculation of kinetic parameters. In the theoretical part, iron alotropy is briefly described, followed by a description of the DSC analysis itself. The thesis also includes division and derivation of isoconversional methods for calculating the activation energy. In the experimental part, a series of measurments is perfomed on pure iron prepared by Cold Spray method. In the paper the influence of deformation on the Curie temperature of the magnetic transformation in -Fe and transformation > is investigated. The activation energy is calculated for transformation > for different degrees of deformation. The degree of deformation is monitored by channeling contrast.
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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.
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Surface melting and possible alloying of cast iron with lamellar graphite by electron beam
Abu Khait, Yosef ; Kouřil, Miloslav (referee) ; Pacal, Bohumil (advisor)
In this thesis, the structural and mechanical changes, which took place in flake graphite cast iron after electron beam surface melting and chrome-nickel surface alloying, were studied. Furthermore, the effect of set parameters on properties and depth of the melted and alloyed region is also analyzed. In the experimental part, the analyzed microstructures, micro-hardness and the distribution of elements after melting and alloying, were presented. Structural differences of material regions caused by melting were described based on microstructures. In the end of diploma thesis, the conclusions of using EB technology for surface melting and alloying were discussed.
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Rotary flash hardening with help of electron beam and laser radiation
Klusáček, Martin ; Jan, Vít (referee) ; Kouřil, Miloslav (advisor)
This master thesis deals with surface hardening of steels, especially with rotary flash hardening of 42CrMo4 steel (WNr 1.3563, ČSN 15142). In this method homogenous heating of whole surface occurs during a very fast rotation of the component. In the theoretical part of this thesis the most common methods of surface hardening are described, with focus on laser and electron beam technologies. In the experimental part special device for this application was constructed. Rotary flash hardening was done using different radiation source and experimantal device parameters. The hardened surface layer of maximal thickness of 0,7 mm and width of 5,6 mm was achieved using laser beam. Results with electron beam were way better, because this technology allows to control the distribution of power along the beam width in order to improve the width/thickness ratio of hardened layer. Using this method maximal layer thickness of 1,4 mm and width of 13,4 mm was achieved.
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Surface treatment of selected steels using electron beam
Oríšek, Petr ; Jan, Vít (referee) ; Kouřil, Miloslav (advisor)
The thesis aims for the surface treatment of materials using electron beam. It includes a literary research describing physical principle and properties of the electron beam. This research also presents possible influencing of the beam and describes the construction of the device that generates the beam. Various applications of the electron beam for the material treatment are presented in the second part of the paper. Within this thesis an experiment with the heat treatment of the steel surface by the electron beam has been realized. The experiment was aimed at creating a layer as deep as possible without melting the surface. The results and their evaluation are presented in the experimental part of the thesis. The attention is also paid to selected process parameters.
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Structure and properties of electron beam penetration produced in steel AMS 5659
Říčan, Daniel ; Foret, Rudolf (referee) ; Kouřil, Miloslav (advisor)
This master thesis deals with the electron beam welding of the AMS 5659 steel used in industry for special hydraulic cylinders (Fig. 1). A theoretical analysis of electron beam welding and analysis of the influence of selected welding parameters on penetration characteristics are in the first part of the thesis. The second part contains an evaluation of the implemented experimental penetrations on samples of the steel in the hardened condition H1025 and after solution heat. It was also done a properties assessment of the same samples that were been hardened again. The light microscopy (SM), the scanning electron microscopy (SEM) and the measurement method of hardness according to Vickers were used for evaluation and comparison of the steel properties in the region of penetration and the heat affected zones properties.
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