Use of scanning electrochemical microscopy as a predictive technique in a salt fog corrosion test

A process for predicting corrosion resistance results which would be obtained for a surface S1 having undergone an anticorrosion treatment if the surface S1 was subjected to a salt fog corrosion test, the process comprising an analysis of the surface S1 by scanning electrochemical microscopy, wherein the analysis comprises the following actions:

• i) measuring, under previously selected operating conditions, a current at n1 different points of the surface S1 by means of a scanning electrochemical microscopy probe to obtain n1 current values, n1 being an integer which is at least equal to 5;
• ii) determining the percentage of the n1 current values obtained in step i) which are greater than or equal to a detection threshold D, any current value which is greater than or equal to D being considered as corresponding to a point on the surface S1 likely to be corroded in the salt fog test;
• and
• iii) determining, from the percentage obtained in step ii), the number N of corrosion points/unit area likely to be presented by the surface S1 if it was subjected to the salt fog test and comparing the number of corrosion points/unit area thus obtained with the maximum number Nmax of corrosion points/unit area that the surface S1 should have to successfully pass the salt fog test, whereby:
• if N is less than the maximum number Nmax, then it is possible to predict that the surface S1 will effectively successfully pass this test, while
• if N is greater than the maximum number Nmax, then it is possible to predict that this surface will not successfully pass this test.