Current Density

Definition

Current density is the corrosion current concentrated over a given area of metal, and high values at a small anode produce rapid localized loss. A small anode paired with a large cathode drives intense dissolution.

When current focuses into smaller and smaller regions of metal, current density rises and metal loss accelerates and localizes. In an oxygen differential cell, a large cathodic surface drives intense dissolution at a tiny anode, drilling through metal at high speed. The same small-anode large-cathode imbalance makes galvanic and under-deposit corrosion especially destructive.

Related concepts

Oxygen Differential Corrosion · Pitting Corrosion · Galvanic Corrosion

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Part of The Blueprint of Water · ⚡ electrochemistry