In our daily life, corrosion can be seen everywhere. There are six main kinds of corrosion and here we will describe each of them and talk about potential solutions.

Uniform corrosion:

It is the most common corrosion in our surroundings. It always emerges on the surface area or fraction of total area. The metal of the surface will remove when suffering uniform corrosion. However, it is easy to be measured and predicted. To protect materials from uniform corrosion, cathodic and anodic protections are frequently applied. Moreover, many methods can prevent it such as coating and painting. In addition, galvanizing and plating can easily prevent uniform corrosion since these methods obstruct the oxygen and water from the surface.

Galvanic corrosion
When two different alloys are coupled presence in the corrosive electrolyte, the more positive alloy will suffer corrosion and lose some metal to protect the other noble one. Consequently, galvanic corrosion often occur at interface and decrease by lengthen the distance between alloys. To prevent galvanic corrosion, cathode and diminutive anode are forbidden in unfavorable areas. Dissimilar alloys can be insulated to reduce the risk as well.

Pitting Corrosion
Pitting corrosion is usually caused by some factors of materials, chloride in surroundings can also cause pitting attack. There will be small caves on the surface when suffering pitting attack. By using the resistance to the environment materials or controlling chloride concentration we can prevent the corrosion. Higher alloys like ASTM G48 can increase the resistance.

Crevice corrosion

To some extent crevice corrosion is similar with pitting corrosion on their performance. The outside of the crevice is oxygen content while chlorides are inside, which make an electrochemical concentration cell: Cathode outside and Anode inside. Using higher alloys can not only improve the resistance of pitting corrosion but also crevice corrosion, moreover, some effective methods like using gaskets or welding works very well.

Intergranular corrosion
In the situation of presence of tensile stress, cracking may occur along grain boundaries. That is intergranular corrosion. In other words, it is the corrosion between grains and crystals. Heat treatment and the use of stainless steels with lower carbon grade can prevent intergranular corrosion.

Dealloying
Dealloying means prating or selective attack. in order to resist dealloying people can select more resistant metals or alloys. Controlling the environment can also be an effective method to reduce the risk of dealloying.