Rust Corrosion Simulator (2D)

This 2D simulator lays a flat iron plate over a grid of microscopic anode and cathode sites and lets a real electrochemical cell run across its surface: anode cells oxidize iron (Fe → Fe²⁺ + 2e⁻) while neighboring cathode cells reduce oxygen (O₂ + 2H₂O + 4e⁻ → 4OH⁻), and rust precipitates in the diffusion zone between them, spreading outward as blotches that darken from green-tinted fresh rust to mature red-brown oxide. Raise humidity to grow the conductive moisture film that lets the reaction run at all, and raise salt concentration to boost the electrolyte's conductivity — both accelerate the corrosion rate exactly as they do on a real steel surface, while the time-speed control lets you watch weeks of rusting unfold in seconds.