Predicting the Steady State Thickness of Passive Films with the Point Defect Model in Fretting Corrosion Experiments

Abstract

The goal is to calculate the steady state thickness of the oxides layer in order to know whether metal is protected or not. Thus thanks to experiments of fretting-corrosion with a sequence of Electrochemical Impedance Spectroscopy, it was possible to use these data with the PDM, Point Defect Model, and to reach the final goal: the prediction of the passive layer of the passive film. First of all, PDM was updated on the fretting process to yield the fretting Model. Thus after 100 minutes of fretting corrosion, the passive film is severely damaged from the modeling results by genetic algorithm. The increase of chlorides concentration allows the destruction of the passive films. However it has been showed that albumin does protect stainless steel against fretting-corrosion degradations. Modeling is in accordance with experiments where 0.1 M of NaCl is a threshold: wear volume was the highest and the steady state thickness the lowest.