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Progress in technology of mold milling with coated profile tools
Doležel, Ondřej ; Bumbálek, Bohumil (referee) ; Píška, Miroslav (advisor)
This diploma thesis is involved in possible development of different types of milling molds coated with modern plows. The first part is devoted to an analysis of contemporary trends in forms production technology. The analysis includes the different types of machines and tools for making various kinds of molds and dies. Another part deals with design of dies for sheet metal shears. The thesis continues by design of the production procedure after heat treatment and finishing die by miling. For milling of die are designed miling tools, the NC program and the possible development of manufacturing the die using a new machining center and the possibility of production optimization. The penultimate point of the thesis is technical and economical evaluation of the direction of development and comparison of positives and negatoves of each method. At the final evaluation is all summed up.
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The Study of Productions Operation Management
Petřek, Martin ; Kouřil, Karel (referee) ; Jurová, Marie (advisor)
The thesis dwells about methodics of processing an order in the company: Hardening shop Frydrych s.r.o. while respecting all the demands on the technological process of thermal and thermo-chemical manipulation as annealing, tempering and cementing. On the bases of the analyse and documental procedures the thesis is unraveling a concept for elimination of absences in the sphere of processing the order also as booking, invoicing and evaluating.
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The Influence of Structure and Heat Treatment on Properties of Steels for Bearings
Pytlíčková, Kateřina ; Dočkal, Ing, Michael (referee) ; Věchet, Stanislav (advisor)
Heat treatment influences structure and characteristics of treatmented material. Good heat treatment of steels for bearings ensures hardness of matrix 60 - 65 HRC, whereas structure has be formed by tempered fine needle-shaped martensite with definite part of residual austenite. Carbides should be evenly dispersed, they mustn´t create carbide network and carbide lines. Quality of steels for bearings is also influenced by volume and morphology of inclusions in the matrix. In this diploma thesis various conditions of heat treatment were to be set up with the aim of choose the optimal ones. These ensures perfect martensite transformation and full hardening of all component. Quenching from 760 °C – 770 °C was quite unsatisfactory. At this temperature resulting structure was ferritic-perlitic, because martensite transformation did not pass. Too long hold on hardening temperature also had unfavourable influence on resulting structure and characteristics. In this case, structure was created by very coarse needle-shaped martensite. Coarsening of martensite needle locally exceeded maximum allowed level. In the structure there was also possible to watch partly soluted globular carbides. Optimal heat treatment is quenching from 850 °C – 870 °C followed by tempering at 220 °C. Resulting structure quite agree with above-mentioned needs. This heat treatment can be recommended for technical practise.
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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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Material selection and heat treatment of blade knives
Mrňa, Tomáš ; Molliková, Eva (referee) ; Němec, Karel (advisor)
A good quality knife should have good cutting features and the edge should be resistant against blunting which can be achieved by using different materials. Steel is the most commonly used material for manufacturing of blades. There are 4 basic categories of steel used for blades manufacturing: unalloyed noble (class 12), low-alloyed (class 13-15), stainless (class 17) and special tool steel (class 19). The optimal combination of structure and features of the used material is achieved by tempering process. The goal of my work is to focus on the steel blade and to point out differences between materials used in mass production and steel used by cutlers. Including the possibility of using various unusual materials from already manufactured products. I am also trying to describe each kind of quenching and consequences of wrong processing.
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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.
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Optimization of heat treatement process for alloyed case hardenening steel
Roubalová, Jana ; Pantělejev, Libor (referee) ; Jan, Vít (advisor)
This bachelor’s thesis deals with the assessment of the influence of heat treatment on the microstructure and mechanical properties of medium alloyed steel 18CrNiMo7-6. The work contains assessment and further proposal of suitable austenitizing temperature for heat treatment. To select the optimal variants of heat treatment five different temperature modes were tested. The theoretical part describes the various methods of heat treatment, with a focus on medium alloyed steels. The practical part presents microstructure of the evaluated steel, its hardenability and hardness depending on the temperature regime of treatment.
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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.
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