Absrract
CuNi90/10 has been used for many decades as a corrosion resistant alloy for seawater applications. Its corrosion resistance mainly results from the formation of a stable, thin and very adhesive protective layer that forms in contact with seawater. The formation of this protective layer can take up to several weeks depending on environmental influences such as temperature, oxygen content or pH value. There is a delay in the formation of a natural protective layer particularly in the case of brackish water. During this time the material is susceptible to corrosion. For this reason, efforts are made to accelerate the process of protective film formation. A typical method is to introduce inhibition with Sodium Diethyl Dithiocarbamate (SDD). Due to its environmentally damaging impact, this method of inhibition and the resulting disposal obligations is a very expensive process. Therefore the formation of a protective layer under naturally occurring conditions and the conditions under inhibition using SDD is being investigated. The goal was to compare both types of protective film formation and estimate whether inhibition with SDD has advantages in corrosion resistance of CuNi90/10 compared to a natural protective film in water from the Weser river.
