Understanding Stray Current Corrosion on Metal Fittings Used in Construction

Posted on

Do you want to set up a resort or holiday destination? Consider coming up with a place where people can enjoy outdoor activities such as swimming, grilling, picnics or ball games. For this, you will need to throw in a few metal fittings for pool railings, boundary demarcations and sporting goal posts, among other uses. Metallic fittings are renowned for their durability and sturdiness, but you must pay attention to corrosion that affects the aesthetics and functional value of your metal fittings. Stray current is one of the notorious causes of corrosion for your fittings. Here is a comprehensive look at stray current corrosion to help you gain insight:

What Is Stray Current and How Does it Come About?

Stray current is electricity that flows through equipment, buildings or the ground because of the power supply flaws or imbalances in a certain area. Notably, one of the safety mechanisms used in power supply channels involves diverting the electric current to the ground through an earth wire. These electric charges stay put in the ground and find their way to metal fittings through good conductors such as groundwater and some rocks like graphite.

What Conditions Promote Stray Current Corrosion?

Some metal fittings will undergo stray current corrosion more rapidly than others will. If the resort is located in a coastal environment, corrosion will be more rapid considering the general saline conditions of the ground and atmospheric water. Saline water conducts electric charges faster compared to fresh water, aggravating the process. Moreover, regular faults in power supply can raise the level of voltage conducted to the ground and speed-up stray current corrosion.

How Does Stray Current Cause Corrosion?

Stray current corrosion occurs in a more or less similar fashion as other electrochemical reactions. Generally, there are negative and positive charges on the surface of the metal, which facilitate the movement of the electrical charges. As the charges move, they cause corrosion at the point they are departing from. This point is the anode (negatively charged area) of the metal reaction.

How Does Cathodic Protection Prevent Stray Current Corrosion?

Cathodic protection refers to the use of sacrificial metals to prevent the corrosion of metallic structures and fittings. Using magnesium or aluminium anodes transfers the anode role from the metal fitting material to the magnesium or aluminium anodes. This inverses the anodic movement of the stray current and diverts its corrosive effect. The stray current reaction, therefore, affects the sacrificial anode coating rather than the material used to make the fittings. To learn more about using cathodes, contact a company like Carman Heating.