One of the most pertinent threats to successful operations in the energy sector is internal corrosion of carbon steel pipework when transporting high temperature (>120oC) aqueous media. The most common method of corrosion mitigation for carbon steel pipelines is via the addition of corrosion inhibitors to process fluids.
However, such chemicals typically have a poor environmental profile and typically lack the required efficiency at elevated temperatures. This research focuses on harnessing the protective properties of corrosion products which naturally form on the internal walls of carbon steel when exposed to high temperature aqueous media. The most commonly observed corrosion product at elevated temperature is magnetite.
Although magnetite has been shown to provide an effective barrier to uniform corrosion of carbon steel, its electrically conductive nature allows this oxide to support electrochemical reactions which results in localised corrosion occurring through galvanic effects.
The intention of this proposal is to identify a method of augmenting the magnetite structure to suppress its electrochemical activity, producing a layer which provides superior protection against both general and localised corrosion compared to conventional corrosion inhibitors. In order to augment the magnetite layer, a method of co-precipitation in the presence of transition metal ions will be adopted. By selection of appropriate transition metals which exhibit zero or minimal toxicity at the required concentrations for augmenting magnetite, a 'batch' method of treatment, or superior alloyed carbon steels can be developed, eliminating the requirement for continuous injection of corrosion inhibitors.
These approaches will provide more cost effective, efficient and greener alternatives to the deployment of conventional organic corrosion inhibitors.