Within TEC Eurolab’s Materials Analysis Center, metallographic and chemical-physical analyses were performed to characterize the material. The results show that both samples were made from the same extra-soft steel for structural uses, supplied in the rough rolled state, with a homogeneous ferritic-perlitic microstructure, free of discontinuities or metallurgical anomalies. The material is compliant, intact and suitable. The problem therefore lies elsewhere. <\/p>\n Visual examinations, micrographs, and fractographic analysis showed:<\/p>\n Laboratory analysis excludes electrochemical corrosion. Instead, the phenomenon is attributed to Microbiologically Influenced Corrosion (MIC). <\/p>\n MIC is an electrochemical phenomenon in which the presence of microorganisms: triggers, facilitates, and accelerates corrosion reactions. It is typical of wet or aqueous environments: pipelines, wells, reservoirs, underground and marine systems. <\/p>\n Many microorganisms can generate MIC (bacteria, fungi, diatom algae), but in industrial pipelines the most common players are iron-oxidizing bacteria, better known as ferrobacteria.<\/p>\n Ferrobacteria are aerobic microorganisms that derive their energy from the oxidation of dissolved iron in water. Their metabolism is simple but devastating: <\/p>\n Fe\u00b2\u207a \u2192 Fe\u00b3\u207a + ferritic hydroxides<\/strong><\/p>\n The water in the pipeline naturally contains oxygen: this results in minimal oxidation of metallic iron, producing Fe\u00b2\u207a ions. Once active, the bacteria enzymatically oxidize Fe\u00b2\u207a to Fe\u00b3\u207a and produce abundant amounts of ferric hydroxide, a gelatinous deposit that accumulates on the inner wall forming a thick, adherent biofilm.<\/p>\n This biofilm:<\/p>\n The result?<\/strong> An extremely corrosive environment, 10-100 times more aggressive than normal aqueous corrosion.<\/p>\n This corrosion dynamic is self-powered:<\/p>\n The process accelerates until it leads, even in a short time, to widespread and devastating corrosion, with loss of thickness and structural failure.<\/p>\n From a practical point of view, the signature of ferrobacteria is characteristic:<\/p>\n Their origin is natural: they proliferate in iron-rich soils and are carried by the water table within wells, pumps, lift units, filters, and delivery pipes.<\/p>\n In the presence of dissolved iron and oxygen, they rapidly colonize entire sections of pipe.<\/p>\n Ferrobacteria are not pathogenic to humans or animals: they do not cause disease and pose no direct health risk.<\/p>\n The problem they generate is a technical one: in fact, they only affect facilities, because they generate biofilms, alter the color and odor of water, promote corrosion, and can harbor other secondary microorganisms, thus compromising the functionality of infrastructure.<\/p>\n The management of ferrobacteria requires a combined approach: prevention, remediation and appropriate design.<\/p>\n 1.Water treatment (primary prevention)<\/strong><\/p>\n 2. Remediation of contaminated pipes.<\/strong><\/p>\n 3. Design precautions<\/strong><\/p>\n The culprit responsible for damaging the water pipeline turned out to be groundwater, which was naturally contaminated with a population of iron-oxidizing ferrobacteria. The material was in fact suitable for its context of use and used appropriately. <\/p>\n These microorganisms turned a perfectly compliant pipeline into an ideal environment for accelerated microbiological corrosion to the point of complete leakage and water escape.<\/p>\n This case demonstrates how even a suitable material and a properly made implant can become vulnerable when an often underestimated factor comes into play: biology.<\/p>\n![\"\"](\"https:\/\/www.tec-eurolab.com\/wp-content\/uploads\/2026\/04\/campioni-testati-300x169.jpg\")
<\/p>\nTEC Eurolab’s approach<\/h2>\n
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<\/p>\nWhat is Microorganism Influenced Corrosion (MIC)?<\/h2>\n
Ferrobacteria: the “natural chemists” that live in water<\/strong><\/h3>\n
These ions become the biological fuel of ferrobacteria.<\/p>\n\n
The vicious cycle of microbiological corrosion<\/strong><\/h3>\n
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How to recognize the presence of ferrobacteria<\/strong><\/h3>\n
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Are ferrobacteria dangerous to human health?<\/strong><\/h3>\n
How can ferrobacterial corrosion be avoided? The remedies <\/strong><\/h3>\n
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Conclusion<\/strong><\/h2>\n