Properties of painted stainless steel: EIS data analysis

The barrier and adhesion properties in organic coatings are very important for determining the effectiveness in corrosion protection of the system. Th e electrochemical impedance spectroscopy (EIS) characterisation is a very s trong tool for assessing both the barrier properties concerning water and i ons, and the interface degradation causing loss of adhesion. Some examples of EIS data analysis for the characterisation of different organic coatings (coil coating) will be discussed in the special case of stainless steel as substrate. The equivalent electrical circuit modelling the coil coated stainless steel will be presented and the surface finish will be optimised by analysing th e EIS data, in order to enhance the adhesion properties, even in the case o f deformation.