What is corrosion and how does it occur?
Corrosion occurs when a material deteriorates due to environmental factors. Corrosion is a natural process which occurs under the following conditions:
- The presence of moisture
- A metal surface
- Oxidizing agent (also called electron acceptor)
As a result of the process, metal is converted into one of its salts i.e. oxides/hydroxides/sulfides, depending on the material. The metal is chemically unstable and its salt is more stable. One of the most common forms of corrosion is rusting. When iron rusts, the reddish flaky substance that has formed as a result of the corrosive process is iron oxide.
Effects on metal
Corrosion affects metals in a number of ways. When metal structures corrode, their integrity is weakened and they become more prone to collapsing. Once corrosion starts, it can spread rapidly which makes it necessary to be vigilant and prevent it right when it starts.
Corrosion Prevention Methods
Here are some corrosion prevention methods to avoid ruining expensive metal equipment
- Choice of metal being used: One simple corrosion prevention measure is using a metal resistant to corrosion. Aluminum and stainless steel are typical examples of such metals.
- Protective Coating: A cost-effective corrosion prevention method is applying a layer of paint. Paint acts as a barrier between the metal and the elements preventing the flow of electrochemical charge that causes corrosion.
- Controlling environmental conditions: Corrosion is the result of a chemical reaction between metal and certain gases present in the environment. Some examples of those gases include sulfur/oxygen/chlorine content
- Sacrificial Coatings: Corrosion prevention can be achieved by coating the surface of the metal with another metal which has a comparatively higher or lower potential to oxidize. The two kinds of sacrificial coatings are: anodic protection and cathodic protection
- Anodic Protection: In anodic protection, the surface that needs to be protected is coated with a metal that is less reactive (e.g. tin). Anodic protection is used to protect storage tanks that are made of carbon steel which are being used for storing fifty percent caustic soda and sulfuric acid.
- Cathodic Protection: Applying a layer of zinc on the surface of iron alloy steel is an example of cathodic protection. Cathodic protection is used for protecting steel pipelines that carry fuel or water, ship hulls, water heater tanks, and offshore oil platforms.
- Corrosion Inhibitors: Another method of corrosion prevention is the use of corrosion inhibitors. Which coat the metal surface in a protective film.
- Passivation: In this process, a protective material (usually some kind of a metal oxide) is used to provide a layer over the metal surface. This layer is what barricades the surface against corrosion. An example of passivation is the color of the Statue of Liberty. A patina, which is blue-green in color, has developed over the structure which acts as a barrier to corrosion for the copper underneath.
An immediate step that you can take is using the WD-40® Multi-Use-Product. The spray is capable of protecting metal parts for a period of time if exposed to the environment and possible longer the object is kept indoors. It is advised to reapply WD-40 regularly.
You can check out more about how WD-40® Multi-Use-Product prevents corrosion, by clicking here!