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Deformation of tool steels after quenching in vacuum furnaces
Abu Khait, Yosef ; Němec, Karel (referee) ; Pacal, Bohumil (advisor)
In this thesis, the deformation stages, which take place in tool steels after quenching in vacuum furnaces, were studied. This study was focused on the heating and cooling conditions during this type of quenching. In the experimental part, the deformation changes in particular samples made of tool steel after vacuum quenching were analyzed. Minor changes in the volume of samples at higher quenching temperatures compared to lower temperatures were observed.
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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.
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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 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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Heat treatment of tool steels
Tobolík, Stanislav ; Pacal, Bohumil (referee) ; Molliková, Eva (advisor)
This thesis deals with the properties of ledeburitic chrome-vanadium tool steel after heat treatment. Theoretical part contains charakterization of ledeburitic steels, the posibility of manufacturing and heat treatment. There are also briefly describes the principles of the test methods, which were used. The practical part is focused on describing the results of 12 sample groups, with different heat treatment. The results are compared in the final discussion.
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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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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.
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Deformation of tool steels after quenching in vacuum furnaces
Abu Khait, Yosef ; Němec, Karel (referee) ; Pacal, Bohumil (advisor)
In this thesis, the deformation stages, which take place in tool steels after quenching in vacuum furnaces, were studied. This study was focused on the heating and cooling conditions during this type of quenching. In the experimental part, the deformation changes in particular samples made of tool steel after vacuum quenching were analyzed. Minor changes in the volume of samples at higher quenching temperatures compared to lower temperatures were observed.
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Heat treatment of tool steels
Tobolík, Stanislav ; Pacal, Bohumil (referee) ; Molliková, Eva (advisor)
This thesis deals with the properties of ledeburitic chrome-vanadium tool steel after heat treatment. Theoretical part contains charakterization of ledeburitic steels, the posibility of manufacturing and heat treatment. There are also briefly describes the principles of the test methods, which were used. The practical part is focused on describing the results of 12 sample groups, with different heat treatment. The results are compared in the final discussion.
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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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