Understanding Root Causes Of Corrosion in The Western Cape
Each year corroded machinery, buildings and equipment cost the world billions of dollars. Corrosion is a costly problem. But by understanding its root causes, effective steps can be taken to prevent and combat it.
There are several types of corrosion costs that industries must consider to fully understanding root causes of corrosion.
Direct loss or damage of metal structures due to corrosion.
An example is a hot water tank that has corroded and must be scrapped.
Maintenance costs attributed to corrosion.
Any metal surface that must be painted every few years to control corrosion falls into this area.
Indirect losses resulting from corrosion.
These losses may result from leakage and fires. Explosions attributed to leakage, power failures, facility shutdown and labor losses are also indirectly the result of corrosion.
The first step toward controlling these costs requires understanding what corrosion is, and what causes it.
What is Rust or Iron Oxide?
When iron or steel corrodes, the result is iron oxide, or what we call rust. Steel is mostly composed of iron ore. In its natural state, iron ore looks much like rust, namely dark red and finely grained, with a tendency to hold moisture.
Iron ore is a stable substance until it is converted into iron or steel, naturally weaker elements. When steel is exposed to moisture and oxygen, it immediately starts regressing to its natural state. Although protective measures have been taken, a large part of the steel made in this century has already rust back to an oxide, its natural state.
Elements Needed For Rust To Form
Three elements are required for corrosion to exist, namely a protected metal, a corroded metal, and a current-conducting medium between the two. When two dissimilar metals are brought into contact, one will become the protected metal, and the other will become the corroded metal. Plant operators may recognize environmental situations that are conducive to corrosion.
Even if a piece of steel is not in contact with another metal, neither under stress nor freshly cut, it will rust when exposed to the weather. This is because steel is not entirely uniform in composition – slight variations in density and composition will occur within a single piece of steel, which results in corrosion.
The third ingredient needed for steel to corrode is an electrolyte. This is normally a liquid or water-containing substance that conducts the corrosion’s current from the protected metal to the corroded metal. The most common current-carrying substance is water. Rain, dew, humidity in the air, etc., all serve as efficient electric conductors. Steel corrodes very slowly in desert climates where humidity is low and rainfall rare. In areas of high humidity and frequent rain, protecting steel is critical.
To learn more about Corrosion and Protection, read the following article.
Contact Protective Coatings Cape Town on 087 550 7676 to discuss your next development project with us.
Topic: Understanding Root Causes Of Corrosion