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Effect of lead and antimony on the degradation of graphite shape in cast iron
Hlobil, Albert ; Kaňa, Václav (referee) ; Záděra, Antonín (advisor)
The bachelor thesis focuses on the effect of lead and antimony on the degradation of graphite in cast iron in relation to the lowered mechanical characteristics. This leads to the subsequent summary of the formation of degraded structures and unfavourable elements – the elements that are the cause of the formation. In the practical segment of the thesis, I will prove the effects of lead (or the combination of lead and antimony) on the degradation of graphite in cast iron with the focus lying at flake graphite. Furthermore, the thesis examines the mechanical characteristics and the attenuation of cast iron in relation to the formation of degraded graphite structures.
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The study of increase in efficiency of manufacturing preparation of technology
Šudoma, Michal ; Lána, Ivo (referee) ; Jurová, Marie (advisor)
This paper discusses different alternatives of more efficient preparation of spheroided graphite cast iron production. Secondary metallurgy and chemical heating technology are used to recast cast iron fused in copula furnace. The work applies the known physical-chemical rules used in the production of quality spheroided graphite cast iron in regular production conditions. Based on the previous developments, the aim was to prepare implementation of verified secondary metallurgy processes in adjusted casting ladle. The casting ladle was adjusted in order to allow execution of all processes required in order for the relevant standards and material lists requirements to be met in respect to spheroided graphite cast iron quality. Comments regarding the trends in ferroalloy metallurgy and related marketing approach of the company. The work is concluded by a summary of advantages brought in by the new approaches compared to the traditional ones from the economical as well as environmental perspective.
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Assessment of probable causes of corrosion damage of a mould made of cast iron
Sobola, Petr ; Pantělejev, Libor (referee) ; Man, Ondřej (advisor)
Bachelor’s thesis deals with solution of problems on glass moulds, which were exposed to the corrosion medium for up to two days causing their damage. The thesis contains theoretical analysis of the problem, layout for the corrosion experiment and its execution. Based on the experiment a conclusion was pronounced that the extent of damage which was observed was not able to be created by corrosion of initial surface without any previous defect.
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Prediction of mechanical properties of lamelar iron castings by means of numerical simulation
Filipek, Szymon ; Hrouzek, Petr (referee) ; Roučka, Jaromír (advisor)
The aim of this thesis was to assess the degree of conformity between the mechanical properties evaluated by numerical simulation in software MAGMA5 and the measured values of hardness and ultimate tensile strength of lamellar graphite iron castings. The theoretical part of this thesis deals with the classification of cast iron, structural components of lamellar graphite iron, and the factors defining the resulting mechanical properties of the material. The practical part presents an attempt to find empirical dependencies between input parameters and results evaluated by simulation software. At the end, an analysis of the correlation between reality and simulation software is performed.
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Penetration of metal into green sand during pouring of iron castings
Ptáček, Tomáš ; Neudert, Alois (referee) ; Záděra, Antonín (advisor)
This diploma thesis deals with the creation of penetration of cast iron with graphite casting cast into bentonite molds. In the first part of the thesis is theoretically described the formation of penetration, its main causes, consequences and the elimination of this defect. The second part analyzes the causes of the defect with the Minitab statistical software and shows the possible connections of the input materials to the occurrence of the defect. Next, the experimental finding of the cause of the defect, which is focused on the measurement of the pressures in the form of the casting, is devoted to it.
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Quality control of the iron castings in the foundry
Krvač, Matěj ; Kaňa, Václav (referee) ; Záděra, Antonín (advisor)
This bachelor thesis deals with the properties of castings with ductile iron and gray iron. The theoretical part was focused on knowledge related to chemical composition, mechanical properties and monitoring of internal defects. In the experimental part, the structure is evaluated in non-etched and etched state. It compares with the chemical component and the mechanical properties with the literature. X-ray frames are monitored for internal defects. In conclusion, the results of the experiments are summarized and measures are proposed to improve the casting quality.
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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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