Rust is scientifically called oxidation, which occurs when oxygen comes in long-term contact with certain metals. Over time, the oxygen combines with the metal at an atomic level, forming a new compound called an oxide and weakening the bonds of the metal itself. Rust consists of hydrated iron(III) oxides Fe2O3·nH2O, iron(III) oxide-hydroxide (FeO(OH), Fe(OH)3. Rusting is the common term for corrosion of iron and its alloys, such as steel. Other metals undergo equivalent corrosion, but the resulting oxides are not commonly called rust.

Paint is any liquid, liquifiable, or mastic composition which after application to a substrate in a thin layer is converted to an opaque solid film.

Coating is a covering that is applied to an object. The aim of applying coatings is to improve surface properties of a bulk material usually referred to as a substrate. One can improve amongst others appearance, adhesion, wetability, corrosion resistance, wear resistance, scratch resistance, etc.. They may be applied as liquids, gases or solids. To protect equipment from environmental damage; many paints, coatings and high performance organic coatings have been developed. Of prime importance in the development of protective coatings was the petroleum industry that produced most of the basic ingredients from which most synthetic resins were developed.

Microbiological corrosion which ensuing loss of metal caused by biological organisms, can occur in any aqueous environments.Because of the omni present nature of microbes in fluid systems, this corrosion is a commonly occurring phenomenon. It is a common problem in industrial processes due to the presence of microbes, adequate nutrients and corrosive byproducts.

Sulfate reducing bacteria form one group of sulfate reducing prokaryotes. Main genus is Desulfovibrio. Desulfovibrio desulfuricans is often used to  immobilize dissolved heavy metals as metallic sulfides. SRB are anaerobes that are sustained by organic nutrients.

Many characteristic features are used in classifying and identifying microorganisms. In general, these characteristic features have been divided into two major categories such as classical and molecular characteristics.

Microbial corrosion ,also called microbiologically influenced corrosion or MIC, is caused by the presence and activities of microbes. This corrosion can take many forms and can be controlled by biocides or by conventional corrosion control methods. Microbes are the first living creatures that have appeared on the earth. They have flourished on the earth for at least 3.8 Ga (Ga= 109 years) of its 4.5 Ga existence. They formed the first biosphere and continue to carry out a multitude of essential geochemical activities that prepared the Earth for the eventual evolution of macroscopic life. Microorganisms are found everywhere in nature, owing to the existence of extremophiles, and adapted to generally hostile environments.

Aluminum is excellent corrosion resistance and its usage as one of the primary metals of commerce to the barrier oxide film that is bonded strongly to its surface and, that if damaged, re-forms immediately in most environments. On a surface freshly abraded and then exposed to air, the barrier oxide film is only 1 nm thick but is highly effective in protecting the aluminum from corrosion.

Aluminium is a highly reactive material. In most surroundings, inside or in the open air, Aluminium has a very high resistance to corrosion. It rapidly forms a thin and dense oxide layer that protects the underlying material very well. The presence of the oxide layer makes aluminium very suitable for many applications. But some environments aluminium may show corrosion behaviour. This section will explain in detail the principles of aluminium corrosion and surface engineering that will enable the right use of aluminium in the right place.

Rust is the common term for corroded steel or iron. The reddish oxide produced is caused by oxygen and moisture. Hydrated Iron(III) Oxide, or rust, has become a problem with the increased use of iron and steel for building purposes today,  Rust is the common term for corroded steel or iron. It is a reddish-brown solid that weakens the iron or steel and can cause it to break and forms when iron is exposed to oxygen and water, the oxygen being found in the air, and the water being found in a variety of different forms, for example, rain, condensation and water vapour in the surrounding air.

Corrosion is derived from the Latin "corrosus" meaning gnawed away.  Corrosion may be further defined as a gradual destruction of a material, a substance, or an entity, usually by solution or other means attributed to a chemical process. Many different corrosion mechanisms exist. The most common types are generally well understood. For each, the process is complex, incorporates many factors, and varies according to metal and specific operating conditions.

Iron and steel, the most commonly used metals, corrode in many media including most outdoor atmospheres. Usually they are selected not for their corrosion resistance but for such properties as strength, ease of fabrication, and cost. These differences show up in the rate of metal lost due to rusting. All steels and low-alloy steels rust in moist atmospheres. In some circumstances, the addition of 0.3% copper to carbon steel can reduce the rate of rusting by one quarter or even by one half.

Pitting is used to describe the formation of small pits on the surface of a metal or alloy. Pitting corrosion is a very severe form of localised corrosion. A characteristic of pitting is that only small spots on the metal surface corrode, but due to the small ratio of the anodic on cathodic surface area, the corrosion pits can grow quickly resulting ultimately in perforation of the metallic structure.

Erosion corrosion is the corrosion of a metal which is caused or accelerated by the relative motion of the environment and the metal surface. It is characterized by surface features with a directional pattern (comet tails, horseshoe marks, etc) which are a direct result of the flowing media. Erosion corrosion is most prevalent in soft alloys (i.e. copper, aluminum and lead alloys).