Livarski vestnik 56 / 2009 number 4
Babette Tonn, Lutz Dekker, TU Clausthal, Germany
New Insights on the Influence of Trace Elements on Nucleation and Grain Growth in Cast Iron Melts Grain Growth in Cast Iron Melts
Mitja Petrič, Primož Mrvar, Jožef Medved, Faculty of Natural Sciences and Engineering, University of Ljubljana
Determination of susceptibility to shrinkage and feeding ability of Al alloys
KRUTIŠ, V., KOVÁČ, M., MECAS ESI s.r.o., www.mecasesi.cz
ESI Group Casting Solution – Numerical Simulation as a Tool of Communication
New Insights on the Influence of Trace Elements on Nucleation and Grain Growth in Cast Iron Melts Grain Growth in Cast Iron Melts
Abstract
Process stability in foundries and an increasing demand on the mechanical properties require a basic understanding of the processes of solidification of cast iron. This is necessary to minimize production costs on one part but also for the reduction of pollution through the production of components made of cast iron as well as their use in machinery and equipment.
A current example is the trend towards downsizing of internal combustion engines to reduce CO2 emissions while at the same time increasing demands on performance and smoothness. The increase in cylinder pressure and combustion temperatures makes it necessary to use sophisticated materials on the basis of iron. The understanding of the effects of trace elements on the nucleation and microstructure formation is an important basis for a targeted development of cast iron materials.
The development of high power densities does not stop at internal combustion engines but also gas and steam turbines in power plants are prone to increasingly higher demands on the performance and efficiency. Operating temperatures of over 550°C will be sought. There is the prospect of a renaissance of cast iron materials that could replace the elaborate and expensive steel castings from these fields.
The mechanisms of trace elements such as Sb, Ce or La in cast iron materials on the nucleation and the shape of the graphite precipitates is still virtually unknown. Numerous publications describe, for example, the positive effect of low levels of Sb on the suppression of chunky graphite in thick-walled spherolitic graphite iron parts, such as in the above mentioned power plant components. Too high levels of this element, however, lead to a degeneration of graphite, which lowers the mechanical properties of a component significantly. Furthermore, the interactions of trace elements is poorly researched and based only on empirical observations.
In the following new methods are introduced that explain the effect of trace elements on nucleation and grain growth in cast iron materials.
A current example is the trend towards downsizing of internal combustion engines to reduce CO2 emissions while at the same time increasing demands on performance and smoothness. The increase in cylinder pressure and combustion temperatures makes it necessary to use sophisticated materials on the basis of iron. The understanding of the effects of trace elements on the nucleation and microstructure formation is an important basis for a targeted development of cast iron materials.
The development of high power densities does not stop at internal combustion engines but also gas and steam turbines in power plants are prone to increasingly higher demands on the performance and efficiency. Operating temperatures of over 550°C will be sought. There is the prospect of a renaissance of cast iron materials that could replace the elaborate and expensive steel castings from these fields.
The mechanisms of trace elements such as Sb, Ce or La in cast iron materials on the nucleation and the shape of the graphite precipitates is still virtually unknown. Numerous publications describe, for example, the positive effect of low levels of Sb on the suppression of chunky graphite in thick-walled spherolitic graphite iron parts, such as in the above mentioned power plant components. Too high levels of this element, however, lead to a degeneration of graphite, which lowers the mechanical properties of a component significantly. Furthermore, the interactions of trace elements is poorly researched and based only on empirical observations.
In the following new methods are introduced that explain the effect of trace elements on nucleation and grain growth in cast iron materials.
Mitja Petrič, Primož Mrvar, Jožef Medved
Determination of susceptibility to shrinkage and feeding ability of Al alloys
Abstract
Method for determination of susceptibility to shrinkage of Al alloys was developed. With this method we can help our selves at design of new castings and feeding systems. Results of this method can be also used for optimization of casting simulation and interpretation of simulation results. Castings of this method were made and analyzed by X-ray analysis, thermal analysis was made and castings were cut to look inside to determine shrinkage porosity. These results were compared to simulation results and on basis of these findings some parameters for simulation program were determined such as heat transfer coefficient and Cut-off parameters for shrinkage porosity determination.
Key words: solidification type, feeding, feeder neck, shrinkage porosity
Key words: solidification type, feeding, feeder neck, shrinkage porosity
ESI Group Casting Solution – Numerical Simulation as a Tool of Communication
Abstract
Abstract
ESI Group as a pioneer in development of software for virtual prototype tests develops a unique global solution called “Virtual Try-Out-Space“ (VTOS) – a virtual testing space. This medium enables continuous improvement of a product during engineering design, prototype manufacture and production. It will enable computer simulation of real behaviour of many physical and mechanical phenomena. This complex solution replaces expensive physical prototypes with a computer model of physical reality. ESI Group uses the latest knowledge of material science with the aim of replacing slow tests and detecting deficiencies of real prototypes. In the field of technological processes the firm offers simulations of casting, forming, welding and heat treatment processes.
Key words: Casting simulation, casting defects
Key words: Casting simulation, casting defects