Studies of gas atmosphere near the metal-mould interface during casting and solidification of ductile iron

• Autorzy: Mocek J. , Chojecki A.
• Języki publikacji: EN

Abstrakty

EN

In sand moulds, at a distance of 3 mm from the metal-mould interface, the sensors of temperature, and of oxygen and hydrogen content were installed. Temperature and the evolution of partial gas pressure have been analysed in moulds bonded with bentonite with or without the addition of seacoal, water glass or furan resin. Moulds were poured with ductile iron. For comparison, also tests with the grey iron have been executed. It was found that the gas atmosphere near the interface depends mainly on the content of a carbonaceous substance in the mould. In the green sand moulds with 5% of seacoal or bonded with furan resin, after the mould filling, a sudden increase in the hydrogen content and the drop of oxygen is observed. This gas evolution results from the oxidation of carbon and reduction of water vapour in the mould material, and also from the reduction of water vapour and alloy reoxidation. In carbon-free sand, the evolution in the gas composition is slower because water vapour is reduced only at the interface. Changes of oxygen and hydrogen content in the controlled zone are determined by the transport phenomena.

Słowa kluczowe

EN

ductile iron; metal mould interface; gas evolution; surface of castings

PL

żeliwo sferoidalne; emisja gazu; powierzchnia odlewu

• Wydawca: Komisja Odlewnictwa Polskiej Akademii Nauk Oddział w Katowicach
• Czasopismo: Archives of Foundry Engineering
• Rocznik: 2012
• Tom: Vol. 12, iss. 4
• Strony: 166--170
• Opis fizyczny: Bibliogr. 11 poz., tab., wykr.

Twórcy

autor

Mocek J.

autor

Chojecki A.

• AGH University of Science and Technology, Reymonta 23, 30-059 Kraków, Poland,

Bibliografia

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• [5] Chojecki A. & Mocek J. (2012). Effect of atmosphere in a foundry mould on casting surface quality. Archives of Foundry Engineering / Polish Academy of Sciences. Commission of Foundry Engineering. Vol. 12 iss.1, 13-18.
• [6] Mocek J. & Samsonowicz J. (2011). Changes of gas pressure in sand mould during cast iron pouring. Archives of Foundry Engineering / Polish Academy of Sciences. Commission of Foundry Engineering. Vol. 11 iss. 4, 87-92.
• [7] Winardi L. (2008): Variables affecting gas evolution rate and volume from cores in contact with molten metal. AFS Transaction, v. 226, pp 505-521.
• [8] Mocek J. & Chojecki A. (2009). Evolution of the gas atmosphere during filing the sand moulds with iron alloys. Archives of Foundry Engineering / Polish Academy of Sciences. Commission of Foundry Engineering. Vol. 9 iss. 4, 135-140.
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• [10] Chojecki A., Sobczak N., Mocek J., Nowak J. & Siewiorek A. (2012). Gas evolution from heated bentonite bonded moulding sand. International Journal of Cast Metals Research. IJC 1102, Accepted 31.03.2012.
• [11] Orlenius J., Dioszegi A. & Dioszegi Z.(2008) Gas absorption in gray iron during mould filling. International Journal of Cast Metals Research. Vol. 21, 427-434.