Subsea cooling nowadays does require complex material systems to be able to mitigate fouling and corrosion during the lifetime of the module. Galvanic coatings are majorly used to prevent corrosion on the seafloor, which comes with extra thickness and hence decreased heat transfer efficiency. In other cases, biocidal material is used to mitigate fouling from occurrence, but it pays it prize in disturbance of the ecosystem which is something to eliminate.

Presented in this paper is a novelty Surface Treatment, Minimox ©, which might be a game changer in regards to subsea cooling. Minimox does interact very differently with the metallic surface compared to an usual coating. It consists of Yttrium nanoparticles in a water solution which furthermore is adhering to the surface upon heat treatment. The combined Yttrium and Chromium oxide formed on a stainless steel surface implies a drastically decreased Surface Free Energy and hence fouling mitigation occurs. Once the treatment has been implied, the metallic surface chemistry has been changed, and wont be consumed at all over time, causing the “coating” to have infinite lifetime without affecting the heat transfer at all, since the thickness is negligible.

In regards to corrosion, the nanoparticle treatment does imply the phenomenon Reactive Element Effect, which interrupt the corrosion mechanism and prevent localized corrosion attacks.

Results of fouling and corrosion on nickel alloys and stainless steel coupons combined with Minimox are further demonstrated in the paper along with explanations and theory about fouling mitigation.

Jonathan Haglund
Elin Forsling