Corrosion protection

Over time, the metal products are gradually covered with a rusty coating. The structures are destroyed, practically turning into dust. To avoid such sad results, it is necessary to know what corrosion of metals is and how to protect it from it. Metal is subject to destruction due to the influence of the external environment, which is electrochemical or chemical. Chemical corrosion appears in environments that are not capable of conducting electric current (oil products, gases, alcohols). Absolutely all metals are subject to it. Electrochemical corrosion arises from the appearance on the metal of an electrolytic film due to the influence of the environment. In particular, technical and household salts used on roads in winter, and wandering currents have an impact . The methods and methods with which to protect against corrosion, there are many.

The most popular and common is the use of paint and varnish coatings. They are metallic and inorganic non-metallic. A high efficiency is provided by coatings, which are based on synthetic polymers. Inorganic non-metallic coatings are very diverse. These include paints (oil, alkyd and enamel), as well as varnishes (tar, synthetic, bitumen). When applied, this corrosion protection creates a thin film that shields the metal from moisture and external influences. Varnishes and paints are very easy to apply, affordable. At the beginning of the work, it is necessary to strictly follow the technology of their application. Cover them with a metal surface in several layers, in order to better protect the structure from atmospheric influences.

Metallic coatings-inhibitors are of two types. The first include the tread covers with cadmium, zinc, aluminum. To the second - corrosion-resistant coatings with copper, silver, lead, nickel and chromium.

Depending on which mechanism The action is protected against corrosion, it is called cathodic or anodic. There are metal coatings-inhibitors, which have greater electronegativity, and coatings that have greater electropositivity. Anodic coatings belong to the first type, cathode coatings to the second type. Aluminum and zinc are used as anodic coatings, nickel, copper, and tin as cathode coatings.

Various methods for protecting metals from corrosion suggest several coating options. For example, for applying inhibitors, a chemical method of coating metal structures with other metals is used: aluminum, zinc.

If the metal structure is already exposed to corrosion, then additives in the form of passivating agents and inhibitors will help slow down the destruction process. The catalytic processes in alkaline and neutral media inhibit such strong oxidizing agents as alkaline earth and alkali metal salts . To protect the reinforcement in reinforced concrete, use nitrite-calcium nitrate.

When corrosion protection is required, Arising under the influence of the external environment and atmospheric precipitation, use volatile inhibitors that are substances that are adsorbed on the metal surface from the air or condense on it, forming a thin layer.