The work is particularly aimed at metallurgical problems connected with manufacture of castings of weight about 1 up to 40 tons from high-alloy austenitic nickel cast irons also known under the trade name Ni-resist. The main aim is to check and complement the knowledge about manufacture of heavy castings from austenitic nickel cast irons in a field of control of tapping and casting temperature, carbon content control with regard to the prediction of eutectic composition and in a field of setting a suitable chemical composition of cast iron with regard to the formation of chunky graphite and stability of the austenitic matrix and further on also possibilities of cast iron filtration during pouring the castings. Based on done experiments the formulae were determined that enable to calculate eutectic and liquidus temperatures on the basis of chemical composition of the cast iron. The use of several formulae given in the literature for calculating the carbon equivalent of austenitic nickel cast irons was compared and evaluated. For utilization of determined results in practice a calculating programme has been compiled making possible to be used in operational practice. This programme is named Calculation of casting temperature of Ni-resist cast irons. After the entry of the melt chemical composition the programme calculates the all important parameters necessary to know and to be controlled for manufacture of high quality castings from austenitic nickel cast irons. Eutectic temperature, liquidus temperature and then based on it the tapping and casting temperatures are included among those parameters. Further on there are eutectic concentration of carbon, carbon equivalent, nickel equivalent, and a criterion evaluating a danger of chunky graphite formation.
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:234009 |
| Date | January 2012 |
| Creators | Kaňa, Václav |
| Contributors | Elbel, Tomáš, Martínek, Ludvík, Šenberger, Jaroslav |
| Publisher | Vysoké učení technické v Brně. Fakulta strojního inženýrství |
| Source Sets | Czech ETDs |
| Language | Czech |
| Detected Language | English |
| Type | info:eu-repo/semantics/doctoralThesis |
| Rights | info:eu-repo/semantics/restrictedAccess |
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