Corrosion inhibitors are substances that inhibit or slow corrosion processes.
Corrosion is an electrochemical process caused by a difference in potentials between a corrosive element and the solution of electrolyte in which this element is immersed. Then a metal with a lower electrochemical potential forms an anode on which oxidation occurs, as a result of which the ions of this metal pass to the solution. The factors causing corrosion are: oxygen, peroxides, organic acids, carbon dioxide, phenols and hydrogen sulfide. Different types of corrosion can be distinguished, including galvanic, microbiological, pitting and crevice.
Corrosion inhibitors perform protective functions, preventing damage to components made of metals and their alloys. The use of corrosion inhibitors allows prevention or significant reduction in the corrosion process. Their action consists in creating a protective layer on the surface of the material by adsorption of the inhibitor particles. The thin film created in this way acts as a barrier, preventing damage to the material. In addition, inhibitors ensure an appropriate pH level, further limiting corrosion progress.
Several classifications of inhibitors are distinguished, which include their chemical composition (inorganic and organic inhibitors), mechanism of action or corrosive environment. By taking into account their electrochemical action mechanism, we can classify them as:
1) anodic – inhibiting reactions occurring on the anode, otherwise referred to as passivating inhibitors. They react at the boundary of the corrosion material and the environment in which the material is located. They create a layer of oxides in this area, which protects the metal against migration to the environment.
2) cathodic – blocking reactions occurring on the cathode, also referred to as precision inhibitors. They cause precipitation of insoluble deposits of hydroxides and carbonates.
3) mixed – this effect is demonstrated by organic compounds. They affect both the cathodic and anodic processes. This is due to the adsorption on the entire surface of the metal that is in contact with the environment containing the inhibitor.
The substances inhibiting corrosion processes are used in many industries. They are mainly used in the metallurgical industry and in the production of preparations for industrial washing and cleaning. Specialised preparations can be used in various construction elements, such as pipes, boilers, heaters or whole installations. The benefits resulting from their use include: prevention of corrosion in the above-mentioned places, for valves they can reduce fuel consumption, prevent the build-up and formation of scale in boilers, and protect pumps against seizure.
Corrosion inhibitors can be ready-to-use products, introduced into pipes, for example, but can also be used as additives for formulations of processing fluids, paints or metals.
It is important to remember that corrosion inhibitors are not intended to remove the effects of corrosion, but only prevent its development. In order to remove what might have been left before the use of inhibitor, other specialist preparations should be used.
PCC Group offer
The product catalogue of the PCC Group contains a whole range of different corrosion inhibitors. One of them is the Chemax series. The available formulations are designed for the metallurgical industry in particular. We also offer products under the brands Chemeen, Chemfac, Chemquat and Chemstat, which can also be used in other industries. Similar preparations preventing the formation of rust can be found under the name MAxCor.
Maxib is another popular series of corrosion inhibitors. These products are used mainly in processing fluids intended for the metallurgical industry, but also in such industrial cleaning agents as corrosion inhibitors.
