|
|
PROGRESSIVE PRODUCTION PROCESSES AND SIMULATION OF STRUCTURES AND PROPERTIES OF SPHEROIDAL GRAPHITE CAST IRON
Musilová, Iveta ; Mores, Antonín (referee) ; Pacal, Bohumil (referee) ; Šenberger, Jaroslav (advisor)
The thesis is concerned with relationships between progressive technological processes of spheroidal graphite cast iron’s production and their structural properties. The aim of the work is to explain causal relationship between parameters of the proposed manufacturing technology of the iron type given (involving selected variants of modification and inoculation of melt and the parameters of melt crystallization, solidification and cooling down in a mould), their structure and even chemical heterogeneity of elements in this structure. For close specification of presented relationships three-dimensional model of spheroidal graphite growth was used, which was developed at the Brno University of Technology, Faculty of Mechanical Engineering. Its usability in praxis has been verified on the basisis of the application of this model on experimentally acquired data. The U GRAFIT 20 model of the authors Stránský and Million counting segregation in the frame of eutectic cell has not still been used for prediction of segregation in real condition in greater extent. On the basis of the above mentioned model microsegregation within “on average” of the cell has been discovered during experimental melts. Microsegregation has been described by segregation and heterogeneity indexes. Calculated values of segregation and heterogeneity indexes have been compared with experimentally verified values. On the basis of comparison of calculated and measured values the possibility of further usage of the mentioned model in praxis has been explored.
|
|
|
Structure and mechanical properties of thin wall nodular iron castings
Chýlková, Adéla ; Mores, Antonín (referee) ; Roučka, Jaromír (advisor)
The purpose of this final thesis is experimental verification of the influence of graphitic inoculants containing different amounts of trace elements on the structure, mechanical properties and internal homogeneity of thin-walled ductile iron casting. This thesis describes the issue with casting of thin-walled ductile iron. Two melts of thin-walled test plates with thickenesses of 3-, 5- and 8 mm were done in experimental part. A total of six types of inoculations with different content of trace elements were tested. Subsequently, an X-ray irradiation analysis was performed on the samples and hardness, tensile strength and ductility were evaluated. Futhermore, the amount of graphite in structure, graphite shape, graphite size, nodularity, graphite nodule count and volume phases of ferrite and perlite in matrix were analysed in thin-walled ductile cast iron by computer-based image analyzer. Finally, the measurement data were processed into tables and charts and conclusions were formulated. An X-ray analysis proved, that all thin-walled test plates containned shrinkage porosity. Furthemore it was confirmed, that content of manganese in inoculant increases tensile strength and hardness. Also content of zirconium in inoculant increases graphite nodule count.
|
|
|
Structure and mechanical properties of thin wall nodular iron castings
Chýlková, Adéla ; Mores, Antonín (referee) ; Roučka, Jaromír (advisor)
The purpose of this final thesis is experimental verification of the influence of graphitic inoculants containing different amounts of trace elements on the structure, mechanical properties and internal homogeneity of thin-walled ductile iron casting. This thesis describes the issue with casting of thin-walled ductile iron. Two melts of thin-walled test plates with thickenesses of 3-, 5- and 8 mm were done in experimental part. A total of six types of inoculations with different content of trace elements were tested. Subsequently, an X-ray irradiation analysis was performed on the samples and hardness, tensile strength and ductility were evaluated. Futhermore, the amount of graphite in structure, graphite shape, graphite size, nodularity, graphite nodule count and volume phases of ferrite and perlite in matrix were analysed in thin-walled ductile cast iron by computer-based image analyzer. Finally, the measurement data were processed into tables and charts and conclusions were formulated. An X-ray analysis proved, that all thin-walled test plates containned shrinkage porosity. Furthemore it was confirmed, that content of manganese in inoculant increases tensile strength and hardness. Also content of zirconium in inoculant increases graphite nodule count.
|
|
|
PROGRESSIVE PRODUCTION PROCESSES AND SIMULATION OF STRUCTURES AND PROPERTIES OF SPHEROIDAL GRAPHITE CAST IRON
Musilová, Iveta ; Mores, Antonín (referee) ; Pacal, Bohumil (referee) ; Šenberger, Jaroslav (advisor)
The thesis is concerned with relationships between progressive technological processes of spheroidal graphite cast iron’s production and their structural properties. The aim of the work is to explain causal relationship between parameters of the proposed manufacturing technology of the iron type given (involving selected variants of modification and inoculation of melt and the parameters of melt crystallization, solidification and cooling down in a mould), their structure and even chemical heterogeneity of elements in this structure. For close specification of presented relationships three-dimensional model of spheroidal graphite growth was used, which was developed at the Brno University of Technology, Faculty of Mechanical Engineering. Its usability in praxis has been verified on the basisis of the application of this model on experimentally acquired data. The U GRAFIT 20 model of the authors Stránský and Million counting segregation in the frame of eutectic cell has not still been used for prediction of segregation in real condition in greater extent. On the basis of the above mentioned model microsegregation within “on average” of the cell has been discovered during experimental melts. Microsegregation has been described by segregation and heterogeneity indexes. Calculated values of segregation and heterogeneity indexes have been compared with experimentally verified values. On the basis of comparison of calculated and measured values the possibility of further usage of the mentioned model in praxis has been explored.
|
guest ::
