Publication detail

State of the art of metal reoxidation study of iron castings

ELBEL, T. ŠENBERGER, J. ZÁDĚRA, A. VLADÍK, R.

Czech title

Současný stav studia reoxidace u litinových odlitků

English title

State of the art of metal reoxidation study of iron castings

Type

journal article - other

Language

en

Original abstract

Metal reoxidation causes a number of iron castings defects, particularly when pouring them in green-sand 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. 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. 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. 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.

Czech abstract

Reoxidace kovu vyvolává řadu vad litinových odlitků, zejména při odlévání do syrových forem. Jednou z nich jsou bodliny, na jejichž vznik existuje několik hypotéz. Jednou z možných příčin jsou reoxidační procesy v dutině slévárenské formy. Tekutý kov během proudění ve vtokové soustavě a v dutině firmy přichází do styku s kyslíkem ze vzduchu a z vodní páry. Dochází k sekundární oxidaci prvků v pořadí podle jejich afinity ke kyslíku. Autoři se proto zaměřili na litiny. Reoxidace byla zkoumána kromě nepřímých metod hlavně přímým měřením aktivity kyslíku během plnění formy až po teplotu solidu. Kontinuální sledování změn aktivity kyslíku ve slévárenské formě je originálním řešením, protože jiní autoři prováděli svá měření jen v peci sensory pro jednorázová měření. Získané výsledky potvrdily, že měření aktivity kyslíku v litinách může sloužit k řízení jakosti odlitků, ale k objasnění procesů probíhajících v dutině při odlévání kovu je málo citlivé.

English abstract

Metal reoxidation causes a number of iron castings defects, particularly when pouring them in green-sand 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. 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. 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. 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.

Keywords in Czech

reoxidace kovu, měření aktivity kyslíku, litinové odlitky

Keywords in English

metal reoxidation, oxygen activity measurements, iron castings

RIV year

2007

Released

15.11.2007

ISSN

1897-2764

Journal

Archives of materials Science and Engineering

Volume

28

Number

11

Pages from–to

649–652

Pages count

4

BIBTEX


@article{BUT43957,
  author="Tomáš {Elbel} and Jaroslav {Šenberger} and Antonín {Záděra} and Radoslav {Vladík},
  title="State of the art of metal reoxidation study of iron castings",
  journal="Archives of materials Science and Engineering",
  year="2007",
  volume="28",
  number="11",
  month="November",
  pages="649--652",
  issn="1897-2764"
}