This document specifies the electrochemical test for determining galvanic corrosion rate of CFRPs and metal assemblies with protection-coating, subjected to the corrosive environment of electrolyte diffusion through the coating. It specifies the apparatus, the test solutions, and the procedure to be used in conducting the electrochemical tests for
a) the assessment of the Fick's diffusion parameter for protective coating on metallic materials, and
b) the estimation of the galvanic corrosion rates with the conversion of ISO 21746 coating-free sample data.
The following are intended situations of implementing an electrochemical test based on this document:
a) when interested parties estimate the galvanic corrosion rate of bonded joints relating engineering metals with protection-coating and CFRPs of the potential drastically nobler than those of most metals, utilizing the resources of ISO 17475;
b) when expanding CFRP-metal bonded joints applications using coatings to the fields of corrosion-sensitive environments caused by electrolytes.
It is not the intent of this document to fulfil the need for:
— omitting relevant field tests for the applications in corrosive environment;
— superimposing test data for specific applications for the range of relevant data;
— comparative testing as a means of ranking different protections with respect to corrosion rates;
— ignoring the field hazards such as erosion, abrasion, and ultraviolet irradiation.