Tubercle

Definition

A mound of corrosion product built up over a localized corrosion site that shelters the active metal and provides attachment structure.

The characteristic black deposits and sulfide odor beneath tubercles are the signature of sulfate-reducing bacteria activity. Tubercles restrict chemical access and maintain the oxygen-depleted, acidic conditions that drive under-deposit corrosion. They are a physical fingerprint that biology is organizing beneath the visible surface.

Related concepts

Microbiologically influenced corrosion (MIC) · Under-Deposit Corrosion · Sulfate-reducing bacteria (SRB)

---

Part of The Blueprint of Water · 🧱 materials