{"id":1422,"date":"2026-05-30T20:52:04","date_gmt":"2026-05-30T17:52:04","guid":{"rendered":"https:\/\/cfc.codev-eg.com\/?page_id=1422"},"modified":"2026-06-02T21:25:00","modified_gmt":"2026-06-02T18:25:00","slug":"feeding-and-surface-treatment","status":"publish","type":"page","link":"https:\/\/cfc.codev-eg.com\/fr\/products\/metallurgical-chemicals\/ferrous-metal-treatment\/feeding-and-surface-treatment\/","title":{"rendered":"Feeding and surface treatment"},"content":{"rendered":"\t\t
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Division 01 \u2014 Metallurgical \/ Ferrous \/ Feeding & Surface Treatment\n\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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Feeding &\nSurface Treatment<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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Feeding compounds, exothermic and insulating sleeves, and melt surface treatments that control the solidification sequence of iron and steel castings \u2014 keeping risers liquid longer than the casting body to compensate for volumetric shrinkage and eliminate internal voids and surface depressions.\n\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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Every ferrous casting shrinks as it solidifies. Grey iron shrinks by approximately 3%, ductile iron by 3\u20134%, and steel by 5\u20137% by volume. Without sufficient liquid metal fed into the last-to-solidify regions during this contraction, the result is shrinkage porosity \u2014 internal voids that weaken the casting \u2014 or visible surface sinks at heavy sections. CFC Egypt's EGYFEED exothermic feeding compound and EGYCOVER insulating covering compound are the primary tools for controlling this solidification-shrinkage problem. Applied to the top of the riser, EGYFEED generates heat that keeps the riser metal liquid longer than the casting below; EGYCOVER insulates the riser surface to slow heat loss to the atmosphere. EGYSLAG is used for ladle and furnace surface treatment, coagulating slag for clean removal before pouring and reducing the risk of slag inclusions in the casting. Together, these products give foundries control over the full solidification sequence from furnace to finished casting.\n\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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What It Covers\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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Feeding and surface treatment products address the solidification phase of the casting process \u2014 controlling how and when each region of the casting solidifies to prevent shrinkage defects and protect the melt surface from oxidation and slag.\n\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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Exothermic Feeding \u2014 EGYFEED\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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EGYFEED is an exothermic feeding compound applied to the riser top after the pour. The compound ignites on contact with the hot metal surface and generates heat, raising the temperature of the riser metal and extending the period during which it remains liquid. By keeping the riser metal molten longer than the casting body beneath it, EGYFEED maximises the volume of liquid metal available to feed the casting as it contracts during solidification, eliminating internal shrinkage voids in critical sections.\n\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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Insulating Cover \u2014 EGYCOVER\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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EGYCOVER is an insulating covering compound used on ladle surfaces and riser tops to reduce heat loss to the atmosphere and protect the metal surface from oxidation. Applied to the ladle, it maintains metal temperature during transport from furnace to mould, reducing temperature drop and improving pour consistency. Applied to the riser, it slows the solidification rate of the riser metal to extend feeding capacity. EGYCOVER may be used alone or in combination with EGYFEED for combined insulating and exothermic feeding.\n\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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Slag Treatment \u2014 EGYSLAG\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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EGYSLAG is used for surface treatment of metal in ladles and furnaces to coagulate slag and facilitate its clean removal before pouring. Slag inclusions in castings \u2014 caused by slag drawn from the ladle surface into the mould with the metal stream \u2014 are a primary cause of casting rejection. EGYSLAG causes dispersed slag particles to coalesce into a coherent layer that can be cleanly skimmed from the metal surface, reducing slag inclusion risk in the poured casting.\n\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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Riser Design & Feeding Efficiency\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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The effectiveness of feeding compounds depends on correct riser sizing and placement. Exothermic and insulating feeding compounds extend the feeding capacity of a given riser volume but cannot compensate for a riser that is fundamentally too small or incorrectly positioned relative to the casting's thickest sections. CFC Egypt's technical team can support riser calculation, feeding compound selection, and application rate optimisation for casting geometries in grey iron, ductile iron, and steel.\n\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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Where It's Used\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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Feeding and surface treatment is required wherever the casting geometry, section weight, or metal type creates a risk of shrinkage porosity. These are the most common application areas.\n\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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Steel Castings\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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Steel has the highest volumetric shrinkage of all common casting alloys and therefore requires the most careful feeding. All sections of a steel casting above a critical modulus require a riser, and all risers require feeding compounds to extend their thermal life. Pump casings, valve bodies, and structural steel castings are subject to radiographic inspection to class standards \u2014 internal shrinkage porosity is a direct rejection cause. Exothermic EGYFEED applied correctly to the riser top eliminates shrinkage porosity in steel sections that would otherwise require oversized risers and heavy metal yield losses.\n\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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Heavy Ductile Iron Castings\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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Heavy section ductile iron castings \u2014 counterweights, gearbox housings, and hydraulic components \u2014 exhibit graphite expansion during solidification that partially offsets shrinkage, but the balance must be managed precisely through mould rigidity and feeding system design. In rigid no-bake moulds, feeding compounds maintain riser temperature to ensure the liquid metal reservoir remains available throughout the solidification window.\n\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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Pressure-Rated Castings\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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Castings subject to pressure testing \u2014 pump casings, valve bodies, pressure vessel flanges \u2014 require internal soundness across all sections. A single interconnected shrinkage void will cause leakage under hydrostatic test, resulting in rejection and costly repair or scrap. Feeding compound application is a key process control step in pressure casting production, ensuring that risers remain effective throughout the full solidification cycle.\n\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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Automotive & Engineering Castings\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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Thick-to-thin section transitions in complex automotive and engineering castings \u2014 where a boss or flange meets a thinner wall \u2014 are classic sites for shrinkage porosity. Directed solidification, achieved through a combination of chill placement and feeding compound application, ensures that these junctions solidify progressively towards the riser rather than forming isolated liquid pools that cannot be fed.\n\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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Ladle & Furnace Operations\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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EGYCOVER and EGYSLAG are used during metal transfer and holding operations to maintain metal temperature and cleanliness between melting and pouring. Effective slag coagulation and skimming before the pour is one of the most reliable methods for reducing non-metallic inclusions in ferrous castings \u2014 a defect mode that causes machining problems and rejection in critical structural components.\n\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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CFC Feeding & Surface Treatment Products\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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EGYFEED exothermic feeding compound, EGYCOVER insulating cover, and EGYSLAG ladle surface treatment \u2014 the complete CFC Egypt range for ferrous casting solidification control.\n\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
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Frequently Asked Questions\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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Technical questions on ferrous casting feeding and solidification control answered plainly. For riser design guidance and feeding compound selection, contact our technical team.\n\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
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What is feeding in ferrous casting and why is it necessary? <\/div><\/span>\n\t\t\t\t\t\t\t\n\t\t\t<\/path><\/svg><\/span>\n\t\t\t<\/path><\/svg><\/span>\n\t\t<\/span>\n\n\t\t\t\t\t\t<\/summary>\n\t\t\t\t
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Feeding is the supply of additional molten metal to a casting during solidification to compensate for the volumetric shrinkage that occurs as the metal contracts from liquid to solid. Iron shrinks by approximately 3% and steel by 5\u20137% during solidification. Without adequate feeding, this volume reduction manifests as internal voids (shrinkage porosity) or surface depressions in the casting. Risers \u2014 reservoirs of metal attached to the casting \u2014 are designed to remain liquid longer than the casting body and feed metal in as the casting contracts. Feeding compounds applied to the riser top extend the period during which this metal remains available.\n\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/details>\n\t\t\t\t\t\t
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What is the difference between exothermic and insulating feeding compounds? <\/div><\/span>\n\t\t\t\t\t\t\t\n\t\t\t<\/path><\/svg><\/span>\n\t\t\t<\/path><\/svg><\/span>\n\t\t<\/span>\n\n\t\t\t\t\t\t<\/summary>\n\t\t\t\t
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Exothermic feeding compounds contain reactive ingredients that ignite on contact with the hot metal surface and release heat, actively raising the temperature of the riser metal to extend its liquid period. Insulating feeding compounds do not generate heat but form a low-conductivity layer that retards heat loss from the riser to the atmosphere, slowing solidification passively. Combined exothermic-insulating compounds achieve both effects together and are the most widely used type in ferrous foundries. EGYFEED and EGYCOVER from CFC Egypt are formulated to provide effective feeding performance across the range of iron and steel casting section weights.\n\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/details>\n\t\t\t\t\t\t
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What is a covering compound and when is it used? <\/div><\/span>\n\t\t\t\t\t\t\t\n\t\t\t<\/path><\/svg><\/span>\n\t\t\t<\/path><\/svg><\/span>\n\t\t<\/span>\n\n\t\t\t\t\t\t<\/summary>\n\t\t\t\t
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A covering compound such as EGYCOVER is applied to the ladle metal surface or the riser top to prevent oxidation, retain heat, and protect the metal from atmospheric contamination. In ladle covering, it reduces temperature drop during transport. In riser covering, it extends riser feeding time by retarding heat loss. Covering compounds are particularly important in steel casting, where the metal surface oxidises rapidly if unprotected, forming an oxide skin that can be entrained in the casting as inclusions.\n\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/details>\n\t\t\t\t\t\t
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How do I know if my castings have shrinkage porosity? <\/div><\/span>\n\t\t\t\t\t\t\t\n\t\t\t<\/path><\/svg><\/span>\n\t\t\t<\/path><\/svg><\/span>\n\t\t<\/span>\n\n\t\t\t\t\t\t<\/summary>\n\t\t\t\t
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Shrinkage porosity appears as irregular internal voids at the last-to-solidify regions of the casting \u2014 typically at thick sections, at section junctions, and beneath the riser if it runs dry before the casting is fully solid. It is detected by radiography for critical sections, by destructive sectioning during process development, or by ultrasonics. Surface shrinkage appears as a visible depression at heavy section tops. Both indicate inadequate feeding \u2014 the riser is too small, incorrectly positioned, or the feeding compound is not keeping the riser liquid long enough. Increasing exothermic or insulating compound application or resizing the riser is the corrective action.\n\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/details>\n\t\t\t\t\t\t
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What CFC products are used for feeding and surface treatment? <\/div><\/span>\n\t\t\t\t\t\t\t\n\t\t\t<\/path><\/svg><\/span>\n\t\t\t<\/path><\/svg><\/span>\n\t\t<\/span>\n\n\t\t\t\t\t\t<\/summary>\n\t\t\t\t
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CFC Egypt supplies EGYFEED \u2014 an exothermic and insulating riser feeding compound for iron and steel castings \u2014 EGYCOVER, a covering and insulating compound for ladle and riser surface protection, and EGYSLAG for slag coagulation and ladle surface treatment. These products are manufactured at our Sadat City plant. Contact our technical team for riser sizing guidance and feeding compound application rates for your specific casting geometry and metal type.\n\n<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/details>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t