Qualification of thermal sprayed corrosion coatings of thick-walled components (QUAKOS). Final report

The project QUAKOS was focused on the production of a corrosion resistant cladding of the inner surface of thick-walled transport or storage containers using the high-velocity flame spraying technique (HVOF). The central task of the working package was the selection of an appropriate test method for the porosity of thermally sprayed coatings. As alternative to the ferroxyl test electrochemical impedance spectroscopy (EIS) was used to determine the quality of the sprayed coatings. The methodology has to be applicable not only for laboratory tests but also for container components. The geometry of transport and storage containers is complicated due to the interlocking system - a challenge for the thermal spraying technique. The project concluded that the HVOF technique for the coating of thick-walled containers does not fulfill the required process security.