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Analysis of the structure Hadfield steel depending on the load deformation
Darida, Jiří ; Julišová, Martina (referee) ; Klakurková, Lenka (advisor)
This bachelor´s thesis deals with the analysis of the structure Hadfield steel depending on the load deformation. The first part of the thesis determines summary of basic mechanical and physical properties of Hadfield steel, its chemical composition, the influence of alloying elements on the resulting microstructure, manufacturing, heat treatment, hardening mechanisms and its use in technical applications. Attention is also paid to the various types of work hardening among which include explosive strengthening. The experimental part of the thesis is focused on the analysis of samples Hadfield steel, which were stressed by different loading conditions. Analysis of these samples consists of observations of structural changes and measurement of work hardening using microhardness in surface and sub-surface region of the sample. The final part presents the view into the future and overall evaluation of results.
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Casting of manganese steels and their use
Dufka, Martin ; Šenberger, Jaroslav (referee) ; Pernica, Vítězslav (advisor)
Austenitic manganese steel, often referred as Hadfield´s steel after its discoverer, has an irreplaceable place in foundry due to its specific properties. Due to local pressures and shocks, surface of castings is hardened, but the cast core retains its toughness. Thus, manganese steel is used for castings of highly stressed machine parts that are subject to abrasive wear. This bachelor thesis is concerned about methods of production, chemical composition, influence of some alloying elements on properties and structure of steel, heat treatment, material properties, reinforcement mechanisms and types of individual deformation reinforcements. Further attention is paid to the most frequent use of manganese castings in practice.
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Influence of Explosive Hardening on the Structure and Characteristic of Hadfield Steel in Terms of use in the Railway Transport
Havlíček, Petr ; Podrábský, Tomáš (referee) ; Nesvadba,, Petr (referee) ; Schmidtová,, Eva (referee) ; Stránský, Karel (advisor)
The high alloyed austenitic manganese steel, the Hadfield steel, thanks to its good wear resistance of the work surface and maintaining the high toughness of the internal material in the same time, is successfully applied for casted crossings. The crossings are the most dynamic stressed components in the railway turnouts. Thanks to low surface and sub-surface hardness the occurrence of plastic deformation and the progressive wear of the crossing running surfaces can be found since the initial stages of the crossing operational life. One possibility how to increase the surface and the sub-surface hardness and this way improve the dimensional stability and the crossing lifetime as well is to apply the explosive hardening of the crossing running surfaces. The technology mentioned above means the application of the explosives in the imminent nearness to the running surface of the crossing, when the high pressure wave acting within the extremely short period actuates the plastic deformation of the material structure. The work deals with analysis of influence of explosive hardening on the structure and characteristic of Hadfield steel. The explosive hardened samples have the surface and the sub-surface hardness checked and the microscopic analysis and X – ray diffraction is applied, including the TEM analysis as well carried out by the transmission electronic microscope. The characteristics experimental testing including outcomes from assessment of the contact – fatigue load of the explosive hardened Hadfield steel samples are the part of the work as well. As an experiment final part the outcomes of the long –term validation, the surface hardness and wear of the crossing running surfaces of the explosive hardened crossing already installed into the Czech Republic railway track are introduced as well.
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Casting of manganese steels and their use
Dufka, Martin ; Šenberger, Jaroslav (referee) ; Pernica, Vítězslav (advisor)
Austenitic manganese steel, often referred as Hadfield´s steel after its discoverer, has an irreplaceable place in foundry due to its specific properties. Due to local pressures and shocks, surface of castings is hardened, but the cast core retains its toughness. Thus, manganese steel is used for castings of highly stressed machine parts that are subject to abrasive wear. This bachelor thesis is concerned about methods of production, chemical composition, influence of some alloying elements on properties and structure of steel, heat treatment, material properties, reinforcement mechanisms and types of individual deformation reinforcements. Further attention is paid to the most frequent use of manganese castings in practice.
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Influence of Explosive Hardening on the Structure and Characteristic of Hadfield Steel in Terms of use in the Railway Transport
Havlíček, Petr ; Podrábský, Tomáš (referee) ; Nesvadba,, Petr (referee) ; Schmidtová,, Eva (referee) ; Stránský, Karel (advisor)
The high alloyed austenitic manganese steel, the Hadfield steel, thanks to its good wear resistance of the work surface and maintaining the high toughness of the internal material in the same time, is successfully applied for casted crossings. The crossings are the most dynamic stressed components in the railway turnouts. Thanks to low surface and sub-surface hardness the occurrence of plastic deformation and the progressive wear of the crossing running surfaces can be found since the initial stages of the crossing operational life. One possibility how to increase the surface and the sub-surface hardness and this way improve the dimensional stability and the crossing lifetime as well is to apply the explosive hardening of the crossing running surfaces. The technology mentioned above means the application of the explosives in the imminent nearness to the running surface of the crossing, when the high pressure wave acting within the extremely short period actuates the plastic deformation of the material structure. The work deals with analysis of influence of explosive hardening on the structure and characteristic of Hadfield steel. The explosive hardened samples have the surface and the sub-surface hardness checked and the microscopic analysis and X – ray diffraction is applied, including the TEM analysis as well carried out by the transmission electronic microscope. The characteristics experimental testing including outcomes from assessment of the contact – fatigue load of the explosive hardened Hadfield steel samples are the part of the work as well. As an experiment final part the outcomes of the long –term validation, the surface hardness and wear of the crossing running surfaces of the explosive hardened crossing already installed into the Czech Republic railway track are introduced as well.
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Analysis of the structure Hadfield steel depending on the load deformation
Darida, Jiří ; Julišová, Martina (referee) ; Klakurková, Lenka (advisor)
This bachelor´s thesis deals with the analysis of the structure Hadfield steel depending on the load deformation. The first part of the thesis determines summary of basic mechanical and physical properties of Hadfield steel, its chemical composition, the influence of alloying elements on the resulting microstructure, manufacturing, heat treatment, hardening mechanisms and its use in technical applications. Attention is also paid to the various types of work hardening among which include explosive strengthening. The experimental part of the thesis is focused on the analysis of samples Hadfield steel, which were stressed by different loading conditions. Analysis of these samples consists of observations of structural changes and measurement of work hardening using microhardness in surface and sub-surface region of the sample. The final part presents the view into the future and overall evaluation of results.
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