Question

what is corrosion. How it can be controlled​

Answer 1

Corrosion is a natural process, which converts a refined metal to a more chemically-stable form, such as its oxide, hydroxide, or sulfide. It is the gradual destruction of materials (usually metals) by chemical and/or electrochemical reaction with their environment. Corrosion engineering is the field dedicated to controlling and stopping corrosion.

In the most common use of the word, this means electrochemical oxidation of metal in reaction with an oxidant such as oxygen or sulfates. Rusting, the formation of iron oxides, is a well-known example of electrochemical corrosion. This type of damage typically produces oxide(s) or salt(s) of the original metal, and results in a distinctive orange colouration. Corrosion can also occur in materials other than metals, such as ceramics or polymers, although in this context, the term "degradation" is more common. Corrosion degrades the useful properties of materials and structures including strength, appearance and permeability to liquids and gases.

Many structural alloys corrode merely from exposure to moisture in air, but the process can be strongly affected by exposure to certain substances. Corrosion can be concentrated locally to form a pit or crack, or it can extend across a wide area more or less uniformly corroding the surface. Because corrosion is a diffusion-controlled process, it occurs on exposed surfaces. As a result, methods to reduce the activity of the exposed surface, such as passivation and chromate conversion, can increase a material's corrosion resistance. However, some corrosion mechanisms are less visible and less predictable.

Answer 2

Heya user...!!!

Here is ur answer.!!

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What is CORROSION...?????  :

• It is a process in which metal reacts with substances present in the atmosphere to form surface compounds.

• For example , iron reacts with oxygen in the presence of moisture and forms rust.

• Silver turns black due to formation of silver sulphide and copper turns green due to the formation of copper carbonate.

Rust : Fe₂o₃.2H₂O ( Hydrated ferric oxide )

                                              OR

• Metals when kept exposed, it reacts with air moisture, acids and other gases present in atmosphere and get corrode. This process is called CORROSION.

VARIOUS METHODS TO CONTROL THE CORROSION ARE :

• By applying paint.

• By applying oil / grease.

• Galvanizing a metal     ----------->     coating of zinc on metal.

• Anodizing a metal   --------------->  coating of layer of aluminium oxide.

• By making alloys     ------------>    Steel - ( Fe + Ni +Cr )

                                                              Brass - ( Cu + Zn )

                                                               Bronze - ( Cu + Sn )

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I Hope this may help u..!!

@Be Brainly...!!

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