engleski

The effect of electrolyte flow rate on corrosion inhibition by self-assembled films of long-chain phosphonic acid

Phosphonic acids are known for their spontaneous self-assembly on oxidized substrates. They easily chemisorb on many metals and alloys and show good resistance to hydrolysis and therefore they can presents potential ecologically suitable solution for increasing a corrosion resistance of alloys under corrosive condition. While phosphonic acids have become popular surface modifiers for metal oxides in various fields, especially in the past decade, there is still a lack of research on their stability under realistic application condition. One of the parameters influencing the corrosion of equipment materials is the flow velocity, through its effect on mass transfer and other phenomena such as erosion-corrosion. Therefore, the aim of this work is to study the effect of the electrolyte flow rate on corrosion of, unprotected and phosphonic acid modified, cupronickel and stainless steel alloys in river and seawater. The investigation is conducted at laboratory scale by the use of flow loop to simulate real conditions. Electrochemical polarization methods and electrochemical impedance spectroscopy are used to determine protective properties of organic film and the corrosion rate of unprotected alloys as function of flow velocity.

flow condition ; long-chain phosphonic acid ; self-assembled layers

nije evidentirano