Often times, corrosion and rust are frequently used interchangeably. There are distinctions between corrosion and rust, despite the fact that both are the outcome of oxidation processes. This is when the element mixes with oxygen, whether via air or water.
So if there are distinctions between corrosion and rust, what are they?
That’s what this Alphatek blog aims to tell you. We’ll go over what corrosion and rust are, how they’re different, and methods of prevention.
What is Corrosion?
A natural process which results in pure metals transforming into a substance that is unfit and undesirable.
When the process of oxidation begins, it causes both metals and non-metals to deteriorate and may even result in the material structure to degrade. The material may be broken down into its elements of oxides, hydroxides, and sulphides.
Because of this, it is often something manufacturers and owners wish to avoid since it interferes with beneficial qualities of the metal. For instance, iron is recognised for its high tensile strength and durability. Especially when it’s an iron alloy.
But once attacked by rusting, anything iron will start to degrade and lose its structural soundness. Objects may even be flaky or crumbly.
What is Rust?
Any iron products or items containing iron will rust when they’ve had prolonged contact with oxygen particles. Rust will typically always happen when an iron object is in the presence of moisture or air. It occurs quite slowly but once it sets in it can very incredibly damaging.
As a result of rusting, rust is formed and it will appear as a reddish-orange colour which emerges from the oxidation of the iron.
How is Corrosion Different from Rusting?
The main difference between corrosion and rusting is that ruse exclusively affects iron. That includes structures with only partial use of iron as well as its alloys. Steel is one of the most commonly used alloys and it is susceptible to rusting.
Therefore, rust is a type of corrosion. Just only relating to the oxidation of metals with iron properties. And whereas corrosion only requires exposure to air or chemicals on the surface, rusting needs both air and moisture together.
If a chemical does come into contact with a substrate, for corrosion to occur then it has to be corrosive ones such as hydrochloric acid or sulphuric acid.
One of the most obvious signs of rusting is the colour that presents itself on the metal. Different to rust, multiple corrosion processes don’t always present this clearly. Sometimes they present as colours such as blue or green, depending on the compound, but other times it can also just be a case of other visual changes.
For instance, there may not be actual colour change to the metal substrate, but it can show visual changes in other ways. There might be indents or cracks apparent on the structure which are also signs of corrosion having occurred.
All Factors That Affect Corrosion
- Metals being exposed to air which contains gases such as carbon dioxide, sulphur dioxide, and sulphur trioxide.
- Rate of corrosion is increased when the metal materials are subjected to moisture, especially salt water.
- Impurities such as salt being present.
- An increased temperature will also have an effect on corrosion spreading.
- Nature of the medium. For instance, some compounds have naturally formed insoluble layers that protect what’s underneath.
- The acid present in the atmosphere plays a role in corrosion, too. When acids are present in the atmosphere, the corrosion process may be more accelerated.
Prevention
To prevent significant losses, corrosion prevention is crucial. Metals are used to construct the bulk of the structures that we can see and use today. So this includes bridges and buildings, machinery, vehicles and other modes of transport, and even residential items like latches and hinges on doors or windows.
Although corrosion and rusting are highly damaging and causes for concern, extended prevention is possible. There’s a number of treatments used to reduce or stop the damage that corrosion causes on objects.
Particular attention is paid to materials exposed to the elements, seawater, acids, and any other harsh environments.
A popular prevention method is Anti-Corrosion Protective Coatings, something that we can offer you.
Alphatek’s Corrosion Protection Coatings can improve component life greatly whilst also preventing corrosion from spreading. And unless it’s managed straight away, corrosion will seriously affect your machinery and operations.
We’ve made many applications across multiple industries where corrosion is a potentially devastating problem. If these coatings are used for offshore structures where the atmosphere and environment will aid in the process and then spread of corrosion, we know that they need to be efficient.
Anti-corrosion coatings need to withstand whatever that inhospitable environment has to throw at us. They have to be long-lasting. That’s exactly what our bespoke coating solutions are. And why we’ve been supplying to the oil and gas industry for more than 20 years.
Contact Us
If you wish to learn more about our services or just have an enquiry, please get in touch with us.
You can call us on +44 (0) 1706 821 021 or send an email to postbox@alphatek.co.uk.
