Corrosion Rate Temperature Rule

Rule of thumb that corrosion rate roughly doubles for every 18°F (10°C) rise in temperature. Explains the feedwater temperature paradox: hotter water holds less oxygen but reacts far more aggressively.

$$\text{Corrosion rate}\propto 2^{\frac{\Delta T}{18^{\circ }\mathrm{F}}}$$

Variables

Symbol	Meaning	Unit
$\Delta T$	Temperature increase above a reference	°F

Worked example

From room temperature to 140°F (about a 70°F rise) corrosion rate increases by roughly 2^(70/18), nearly fifteenfold, even though dissolved oxygen has dropped by about half.

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Part of The Blueprint of Water