Electrochemical corrosion - the most common type of violation of the integrity of metal structures.This does not necessarily immersing the items in the electrolyte.Often enough of a thin film on the surface of the material.
Electrochemical corrosion of metals occurs to a greater extent as a result of the widespread use of technical and household salt (chloride, potassium and sodium).Most often, these substances are used in winter to quickly remove ice and snow from the streets.Most of all, as practice shows, the damage thus applied underground communications and ground transportation.
Electrochemical corrosion is observed on parts of machines, structures, devices that are in conditions of soil, ground water (sea or river), the atmosphere in the solutions and technical purposes, under the influence of lubricating, cooling products.
may provoke destruction of stray currents, which occur in leakage current part of the electrical circuit to the soil or water, and then - in the structural elements.Where the reverse output (from metals in the soil or water), there is destruction of parts - electrochemical corrosion.Most often stray currents are formed in places where the moving surface transport (trams, railway locomotives on electricity).At the same time, studies show that 1 ampere per year is capable of dissolving 33.4 kg of lead, zinc and 10.7 kg, 9.1 kg of iron.
often involved in the development of the destruction of several factors.
Electrochemical corrosion is a special process.Alloy (or independent material) loses part of the existing atoms.They (the atoms) are in the form of ions moving in the electrolytic solution.Instead of the lost metal particles appear electrons, which charge material negative charge.This electrolyte has a positive charge.Thus, galvanic corrosion forms a galvanic couple.The redox reaction is more conducive to the chemical heterogeneity of the material structure.Aggravating factors in the formation of anodes and cathodes are also areas of permanent deformation, lack of uniformity in coating the metal with a protective film.
observe the destruction of parts and can be at home.This requires three nails, three glasses with brine (salt, dissolved in water), a small piece of zinc, copper wire (insulation should be removed).
first nail falls in a glass with a salt mixture.The second should be to fasten the wire and also put into solution (the second cup).The third nail is omitted in the third container.Leave on for two or three days.After this period, all three will be celebrated nails rust.However, in the worst condition will nail wire, at best - with zinc.This difference is related to the ability of various metals give up electrons.
To protect the material used method of changing its capacity.It should be noted that the technique is not associated with the insulation.As protection are used cathode (anode) method.
This protected structure, the disadvantaged (eg, soil) environment is connected to the cathode (negatively charged electrode) of electric power.Thus, the item becomes the cathode.In the same medium was placed and the old item by attaching it to the anode from an external source.Corrosive process leads to the destruction of the old metal that becomes an anode.
There is also a type of protection and the tread.In contrast to the above, this embodiment provides the use of a particular anode - protector.It is used as a more active than that of the protected design, metal.In the process of stress corrosion protector performs the task of the anode (positive electrode) and destroyed, prevents violation of integrity in the protected parts.
