State of the art of metal reoxidation study of iron castings

• Autorzy: Elbel T. , Senberger J. , Zadera A. , Vladik R.
• Języki publikacji: EN

Abstrakty

EN

Purpose: Metal reoxidation causes a number of iron castings defects, particularly when pouring them in greensand moulds. One of them is pinholes the occurrence of which is explained by several hypotheses. One of possible causes is reoxidation processes in the foundry mould cavity. During its flowing in the gating system and in the mould cavity the liquid metal gets into contact with oxygen from air and water vapour. Secondary oxidation of elements takes place in sequence of their affinity to oxygen. Design/methodology/approach: Therefore the authors were aimed at cast irons. Besides indirect methods the reoxidation was researched mainly by direct measurement of oxygen activity during filling of a mould up to solidus temperature. Findings: The use of oxygen activity measurement for direct study of changes caused by reoxidation processes is limited and that it is more suitable for study of the influence of different factors on cast iron crystallization and graphite morphology. Practical implications: Obtained results have confirmed that oxygen activity measurement can serve to the casting quality control. But it is little sensitive for explanation of processes running in a cavity during metal casting. Originality/value: Continuous monitoring of oxygen activity changes in a foundry mould is an original solution since other authors have done their measurements only in a furnace with disposable sensors.

Słowa kluczowe

EN

metallic alloys; metal reoxidation; oxygen activity measurement; iron casting

PL

stopy metaliczne; pomiar aktywności tlenu; odlew żeliwny

• Wydawca: International OCSCO World Press
• Czasopismo: Archives of Materials Science and Engineering
• Rocznik: 2007
• Tom: Vol. 28, nr 11
• Strony: 649--652
• Opis fizyczny: Bibliogr. 14 poz., il., tab.

Twórcy

autor

Elbel T.

autor

Senberger J.

autor

Zadera A.

autor

Vladik R.

• Department of Foundry Engineering, VSB-Technical University of Ostrava, 708 33 Ostrava-Poruba, Czech Republic,

Bibliografia

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• [3] F. Mampaye, K. Beghyn, Oxygen Aktivity in Cast Iron Measured in Induction Furnace at Variable Temperature, AFS Transactions 114 (2006) 637-656.
• [4] Y. Kurokawa, Observation of Pinhole Defects in Cast Iron Castings by Surface Analysis, AFS Transactions 110 (2002) 629-637.
• [5] M. Hecht, V. Castelhano, The formation of pinholes by reaction between lamellar graphite cast iton and green sand, Fonderie-Fondeur d'aujourd'hui 251 (2006) 12-32.
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• [9] F. Mampaey, The use of oxygen activity measurement to determine optimal properties of ductile iron during production, Proceedings of the WFO Technical Forum, Düsseldorf, 2007, 69-73.
• [10] S. C. Ghorpade, Oxygen Probe Measurements in Cast Iron, AFS Transactions 83 (1975) 193-198.
• [11] S. Hasse, Casting-structure Defects, Schiele & Schön, Berlin, 1999 (in German).
• [12] J. Baier, M. Köppen, Handbook of Casting Defects, IKOErbslöh, Marl, 1994 (in German).
• [13] A. Chojecki, I. Telejko, Steel casting, Scientific press, AKAPIT, Krakow, 2003 (in Polish).
• [14] A. Zadera, Reoxidation processes duting pouring and steel casting defects formation, Sbornik vedeckrch praci VSB-TU Ostrava L (2007) 261-268 (in Czech).