PROSEAL NP-300 is a new conversion coating which not only meets the requirements of the EU Directives on Used Vehicles and the RoHS (Reduction of Harmful Substances) concerning the freedom from chromates but even goes a step further. Passivators frequently contain cobalt components to increase corrosion protection. Due to the special dangerousness of cobalt components it can be expected that they must no longer be used in the foreseeable future.
Consistently with PROSEAL NP-300 a conversion coating has been developed which additionally still meets very high corrosion protection requirements.
Photograph 1 shows nuts after 240 hours of salt spray test according to DIN 50021 SS which had been galvanised in the alkaline cyanide-free process TOPAS 3100 and passivated with PROSEAL NP-300. The associated graphic shows the high white rust resistance of the system. Also on zinc coatings which were deposited from acid electrolytes the corrosion protection is considerably improved.
Photograph 2 shows the corresponding parts after 240 hours of salt spray test, Graphic 2 shows the test frequency. A further increase in the protection value is possible with the sealing SURFASEAL WL 150 specially adapted to the new conversion coating. Here protection values are then reached, which so far were possible only with zinc alloy deposits. For further information please contact us or our field staff.