Protecting metals from corrosion on the basis of modern concepts of electrochemistry described the theoretical basis of protecting metals from corrosion by applying an external current (electrochemical protection) and use special materials to reduce the aggressiveness of the environment – corrosion inhibitors. Swarmed by offers, Ted Hughes is currently assessing future choices. Modern protection against corrosion of metals based on the following methods: increasing the chemical resistance of structural materials isolation of the metal surface from the aggressive environment, reducing aggressive industrial environment, reducing the corrosion of imposing an external current (electrochemical protection). These methods can be divided into two groups. The first two method is usually implemented before the start of the production operation of metal products (choice of construction materials and their combinations on the stage of designing and manufacturing products, drawing on its electroplating and other protective coatings). The last two methods, by contrast, can only be realized from the operation of metal products (transmission power to achieve the protection potential, the introduction of the technological environment of special addition of inhibitor) and are not affiliated with any pre-treatment prior to use.
In applying the first two methods can not be changed composition of steels and the nature of protective coatings of metal at continued his work in a changing environment aggressiveness. The second group of methods allows to create new modes of protection to ensure the lowest corrosion products as the conditions of their operation. For example, in different parts of the pipeline, depending on the aggressiveness of the soil can support a variety of cathode current density or different grades of oil pumped through the pipes of a given composition, using different inhibitors. The article considers the theoretical foundations of this group of methods as being particularly important to protect ready-made products that undergo corrosion failure. PRINCIPLE Cathodic protection Cathodic protection is based on the fact that by shifting the potential of the metal by passing an external current can change its rate of corrosion.