Slag is the issue, so why not approach the problem by eliminating slag formationrather than dealing with its presence? Experience does not equal expertise. In some foundries, experience has consolidated into bad habits and/or misunderstanding. For example, recently an electric furnace expert asserted that “the only reasonable method of cleaning the inductor channel is to rod it mechanically.” Others recommend special fluxes to remove slag build-ups in electric furnaces. It is much simpler and safer […]

Foundries that are adding pig iron to electric furnace charges should reevaluate the technical and financial justifications for its effectiveness in producing quality ferrous metal castings. Many ferrous foundries operating electric furnaces include pig iron in their furnace charges, although many of those operators responsible for preparing those charges have only vague ideas to explain why it is so. This is hard to understand, particularly as pig iron is a major expense in iron melting. […]

Iron foundries that are not deoxidizing their melts are missing out on technological advancement – as well as improvements in productivity and metallurgical quality. Ferrous foundries that are not deoxidizing molten iron are missing out on some of the latest advancements available for process and product improvement. Deoxidized iron delivers such major improvements in material quality that it can be understood as a new metallurgical grade, one that yields better quality castings and improves the […]

In both gray iron and ductile iron, a cleaner iron matrix substantially increases the material’s tensile strength – and improves foundries’ processes and casting quality. In both gray iron and ductile iron metallurgy, deoxidation not only produces a cleaner iron matrix but also a material that is substantially stronger. For gray iron, Class 30 iron strength nearly reaches Class 40 strength levels, without alloying. In ductile iron, deoxidized base iron produces near 100,000 psi tensile […]

The reduced tendency to carbide formation in deoxidized iron has been replicated at multiple foundries, each one reporting similar results regarding the carbide-forming tendencies of deoxidized iron. Metallurgical results for deoxidizing iron at one of seven different foundries All iron that is conventionally melted contains a small volume of free-oxygen atoms. Typical free-oxygen atom levels range from 0.0003% to 0.00010% which is expressed as 3 to 10 parts per million (PPM.) This is a very […]

Very small quantities of free-oxygen atoms have a profound effect on molten iron, and it’s up to executives and managers to grasp the big picture. Foundries are reluctant to try new technology. Ferrous foundry operators maintain a tolerance for slag-filled ladles containing iron with small amounts of free oxygen – not believing that may affect the quality of the whole mass of molten metal. Conventionally melted iron contains 4-10 PPM of free oxygen, which changes […]

Ferrous foundries’ results can be improved once metallurgists and operators understand the role of oxygen – and how and why casting defects form. Since the beginning of the Iron Age 2500 years ago, all molten iron has contained free-oxygen atoms and those atoms have significantly corrupted its melting and pouring properties. Free oxygen contamination occurs in tiny amounts but those few parts per million (PPM) alter the iron’s behavior and properties. Deoxidized iron’s properties are […]

Deoxidization is not impossible, and foundries that eliminate free oxygen in the melt are revealing an impressive list of material qualities, along with reduced casting scrap rates. 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 […]

Oxides always form when oxygen atoms are present, and the risk of them agglomerating and reaching the casting surface is unnecessary gamble when deoxidation is possible. Casting surface defects seem to come and go regardless of what the gating specialist may accomplish, or what standards the foundry’s QC depart may change or tighten. Casting surface defects may be gaseous, or they may contain precipitated solid material, but generally such defects fall beyond normal quality-control efforts. […]

Oxidation is a natural effect, but eliminating the process of slag formation is simple, and the results can be significant for material quality and foundry productivity. Regardless of the iron melting technique — EF or cupola — slag will form during the process. Slag consists of oxides that form during the melting cycle. The driving force for oxide formation is the contact of molten iron with the atmosphere, which forms iron oxide, starting the oxidation […]