All iron melted via conventional techniques contains free-oxygen atoms. The amount of free-oxygen contamination varies depending upon the melting method and materials melted, but some free-oxygen atoms always exist.
Free-oxygen atoms are detrimental to the quality of solidified castings. They offer no benefits – only bad consequences from their presence.
Primary steelmakers deal with free-oxygen atoms’ presence by adding aluminum and other high-oxygen-affinity materials. A foundry or any manufacturer that melts iron cannot employ the same oxygen-atom-eliminating techniques. Iron foundries must seek other methods to control oxidation.
For a very long time iron foundries accepted oxidation as inevitable. Slag formation was thought to be a fundamental part of melting. Oxidation always occurred, and it could not be avoided. Most melt deck managers and operators tried to make the best of a bad situation.
The issue of oxidation has changed. For the first time since the beginning of the Iron Age, about 2500 years ago, iron can be melted without carbon and silicon oxidation losses. It is been shown now that iron melting can occur without oxidation.
The new deoxidizing material, Mastermelt DeOX. DeOX is a silicon carbide-pet coke blend that aggressively attacks the source of free-oxygen atoms – iron oxide – contacting the molten iron bath.
Much has been written recently regarding molten-iron deoxidation during or after the melting cycle, but the end result – de-oxidized iron – presents many metallurgical properties and characteristics that are notable improvements over typical ductile iron or cast iron.
Cleaner iron – less nano-sized suspended oxides. Once the molten iron is de-oxidized, a remarkable new material emerges. Iron without large quantities of suspended nano-sized oxides is a much “cleaner” metal. When the free-oxygen atom supply is cut-off, the Laws of Thermodynamics still apply, meaning the precipitation of the free-oxygen atoms with other elemental atoms in the melt. The subsequent agglomeration and buoyancy of the oxide mass means that those impurities soon attach to the bath’s cover slag layer.
This is a very important point: Molten iron self-cleanses when the supply of free-oxygen atoms is cut-off, and DeOX Metal Treatment accomplishes that. The reaction time for the oxygen atom to unite with some other atom in the molten metal bath is 1-2 minutes, at a maximum. The time for agglomeration to complete is longer, and still unknown at this point.
Read more: Exciting New Properties in Molten Iron