Previous researchers have numerically modelled the crevice corrosion of particular classes of metals, and alloys. Applicable to passive metals immersed in an appropriate electrolyte, a new crevice corrosion model simulates the general passive crevice corrosion problem. Rapid approach of chemical equilibrium is assumed. Equilibrium constants and transport properties are adjusted for elevated temperature via the correspondence principle (Criss and Cobble, 1,964) and the Nernst-Einstein equation, respectively. The corrosion rate is adjusted for thermal and acidity effects via an Arrhenius expression and a Freundlich isotherm, respectively. Presented in a sequel publication, the predictions compare favourably with experimental results.