How Do We Control Corrosion?

Before we answer the above question, firstly we must know what Corrosion is.

Corrosion is the deterioration of a material, usually a metal that results from a reaction with its environment. Deterioration means loss of its natures. For metal, the common natures such as : strenth, flexibility, and etc.

The strategies for corrosion control include:

• Design. Designing the structure with corrosion prevention in mind and selecting corrosion-resistant materials when constructing.
• Coating. The application of protective coatings which can serve as barriers to corrosion environments.
• Cathodic Protection. The use of direct electrical current and sacrifacial material (anode) to mitigate corrosion.
• Electrochemical Chloride Extraction.

Corrosion can cause numerous problems, such as environmental and safety. Environmental problems for examples: drinking water systems can become contaminated when the pipelines or storage tanks attacked by corrosion. Safety also threatened as result of the steel bridge structures weakened by corrosion.

There are four methods commonly used to control the corrosion, are:

1. Coating/Painting. This is the principal tools for defending against corrosion, as a barrier with surrounding environment. This substances are often applied in conjunction with Cathodic Protection Systems to provide most cost-effective protection for a structure.
2. Cathodic Protection. Cathodic Protection is a technology which use direct electrical current to counteract the normal external corrosion of structure that contain metal, such as underground petroleum storage tank, natural gas pipeline buried underground, or submerged in water. On new structures, CP can help prevent corrosion from starting.
3. Material Selection. Its refer to the selection and use of corrosion resistant materials such as stainless steel, plastics, and special alloy to enhance the lifespan of the structure as well as the environment in which structure will exist.
4. Corrosion Inhibitors. Inhibitors are the substances (chemical) which  when added to particular environment, decrease the rate of attack of that environment on a material such as metal. It will make a thin film on the surface of a structures. They can help extend the life of equipment, prevent system shutdowns and failures, avoid product contamination, prevent loss of heat transfer, and preserve the appearance.

Evaluating the environment in which a structure is or will located is very important to corrosion control, no matter which control method is used. Modifying the environment immediately surrounding the structure, such as Air Conditioner and modifying the drainage, can be a simple and effective way to reduce the potential for corrosion.

extracted from the course materials and related sources.