The effects of film-forming amines on flow-accelerated corrosion
University of New Brunswick
The effects of Film-Forming Amines (FFAs) on the mitigation of Flow-Accelerated Corrosion (FAC) have been investigated under single-phase and two-phase power plant feedwater conditions. Experiments were carried out in high-temperature and high-pressure recirculating water loops that were equipped with experimental probes for online FAC monitoring. Results showed that the FFAs gave more FAC protection to carbon steels than simple alkalizing feedwater under single-phase conditions; however, they exhibited no extra effect than that of pH under two-phase flow. Under single-phase water, FFAs protect metals from corrosion by adsorbing and forming a durable film on their surfaces. The film in the experiments consisted of several layers and survived for several days after the FFA was removed from the bulk water. FFAs, however, could not form protective films under two-phase steam-water conditions; they partitioned with alkalizing component to the vapour-phase. Hydrophobicity of the surface indicated the FFA affected areas, but did not relate to FAC-mitigating mechanism. Findings of this work prove the ability of FFA products in reducing FAC and can lead to product improvements to suit the needs of corrosion treatment in industries. Minimizing FAC benefits many industries by reducing losses and damage, increasing profitability and increasing safety in the workplace.