Corrosion is a natural process occurring whenever a material is exposed to adverse conditions. This degradation happens any time a metal is used outside of its natural environment. Thinking back to high school chemistry class, approximately 75 percent of the periodic table is classified as metallic, including elements such as potassium. Pure metals — silver, gold, and copper — are less prone to corrosion as they exist in nature. Unfortunately, they are also very expensive; thus, making them cost prohibitive for industrial use.
Most industrial metal is actually an alloy, or a mixture of metal and some other product. Steel, one of the most commonly used industrial metals, is a mixture of iron and carbon, though it may also contain other elements. Iron, on its own, is unsuitable for industrial use as it is soft and corrodes easily. Combining iron with carbon, however, produces a strong, corrosion resistant steel alloy that can be used for anything from girders to tanks to pipes.
“Corrosion resistant” is not the same thing as indestructible, though. Steel is subject to the same basic forms of corrosion as other alloys. The four main corrosion types include:
- General Attack Corrosion affects the entire surface and results from chemical or electrochemical reactions. This type is easiest to prevent as it is a predictable, known occurrence.
- Localized Corrosion is contained to one portion of the surface and is caused by pitting, stagnation, or weakness in the metal’s coating. Each corrosion type allows water or another agent to attack the bare metal.
- Galvanic Corrosion happens when two different metals are in an electrolyte such as saltwater, causing the molecules of the one metal to be attracted to the other metal. In this instance, only one of the two metals will corrode.
- Environmental Cracking has an external cause, such as the earth’s weight pressing down on an underground tank, stressing the metal to the point of cracking or breaking.
How was corrosion treated in the past? The first anti corrosion patent arrived in 1625 and contained copper, iron powder, and cement. But, this technique could not be used on steel hulled ships due to the chemical reaction between copper and steel. By the early 1900s, scientists were experimenting with corrosion prohibitive pigments. And, while Edison experimented with cathodes, it wasn’t until the late 1930s that cathodic protection became a viable option in Bahrain’s oil fields.
Today, rubber lining provides a practical and cost efficient anti corrosive. While localized, galvanic, and environmental corrosion and cracking are unpredictable, the effects of general attack corrosion can be ameliorated by lining metal tanks and pipes. Rubber lining not only mitigates the corrosive nature of your product, extending the container’s life, but it also prevents outside contaminants from entering your product. Lined tanks and pipes also require less maintenance, and little repainting or resealing on a regular basis. This saves you time and money.
For more information regarding rubber linings or any of the other fabricating services we offer, please contact Moon Fabricating online or call 765.459.4194.