While it does obviously have significant financial implications, concerns over metal corrosion also pose safety and health concerns as well. Which brings us back to why it is so important to try and prevent corrosion as much as possible. Metal corrosion is a natural phenomenon that requires three conditions: moisture, a metallic surface, and an oxidizing agent called an electron acceptor.
Corrosion converts the reactive metal surface into a different form which is either oxide, hydroxide, or sulphide. A commonly known form of corrosion is rust. Corroded metal not only affects the metallic structure, but it can also affect the people using the item or things that are within the vicinity of the metal as well.
While all metals are susceptible to corrosion, some metals, like pure iron, corrode much more quickly than others. However, iron can be combined with other alloys to make stainless steel which has the ability withstand corrosion much more. These metals are so well made that they have a higher ability to resist corrosion and using them reduced the need to implement addition corrosion protection measures.
Different materials are selected by our clients for different environments, with one of the main factors being considered is the probability of corrosion. Another way to prevent corrosion is to apply a coating of special protective paint.
Paint coatings can act as a barrier that works by preventing the electrochemical charge transferring to the corrosive solution and the metal underneath. Another way of doing this is to apply a powder coating to the clean metal surface.
The metal is heated to fuse the powder into a smooth unbroken film that acts as a corrosion resistant barrier. Many different powder compositions can be used, such as acrylic, polyester, epoxy, nylon, and urethane. Corrosion is certainly something that is caused by the environment that the metal is in as the chemical reaction that takes place is due to the metal reacting to the liquids and gases in the surrounding area.
Controlling the environment therefore can help to minimise these reactions. This can be as simple as reducing the exposure to rain or seawater or could be steps taken to reduce the amounts of sulphur, chlorine, or oxygen in the area. As an example, treating water in water boilers to adjust hardness, alkalinity, or oxygen content, before exposing the metal to that water would go a long way in helping to prevent corrosion. Sacrificial coating to prevent corrosion means coating the metal with an additional metal type that is likely to oxidise — you sacrifice this top layer in order to protect the metal underneath.
Corrosion inhibitors are chemicals that are chosen to react with the surface of the metal or the surrounding gases and therefore suppress the electrochemical reactions that can lead to corrosion. When they are applied to the surface of a metal, they form a protective film. Inhibitors can be applied as a solution or as a protective coating using dispersion techniques.
Corrosion inhibitors are commonly applied via a process known as passivation. An example of passivation is the Statue of Liberty where the signature blue-green hue of the metal actually is there to protect the copper underneath.
Plating is very similar to coating as a thin layer of metal is applied to the metal you actually want to protect.
As well as preventing corrosion, the metal layer provides good aesthetic finishes. Modifying the design of a project can have a significant impact on preventing corrosion as it works by removing the possible causes of corrosion.
Not only can it inhibit corrosion, but it can also significantly improve the durability of any protective anti-corrosive coatings that have been applied to the products being used. Designing a structure to ensure that the metal is easily accessible for regular maintenance is also good practice and will help to prevent corrosion and increase the life of the metals being used.
Fast, efficient delivery to your exact specification. Like all of the ways to prevent rust, galvanizing has limitations. Galvanizing also changes the outward appearance of the metal, and the extra layer can cover up parts of the component, such as the threads on a screw.
The process of blueing steel actually creates a new layer that is similar to rust, but much less damaging. Blueing creates a layer of magnetite, also called black iron oxide, and gives metals a black or namesake blue appearance.
Blueing is usually accomplished by applying high temperatures and a salt solution. This process is commonly used to economically protect firearms from rusting. Blueing works best when the steel is also regularly oiled.
First, static electricity binds a powdery substance made from acrylic, polyester, epoxy, polyurethane or something else to a metal object. Then, the powder melts in a furnace into a uniform, solid layer. Powder coating, like painting, covers a metal component in a protective layer. This layer will prevent moisture from reaching the metal and therefore prevent rust.
For powder coating to effectively prevent rust, the coating must be intact. Any weak areas will expose the metal and create an entry for rust. VCI Packaging is an easy-to-use, clean and dry packaging option for preventing rust from metal and metal parts. Vapor corrosion inhibitors VCI are a type of chemical compound used to protect ferrous and non-ferrous metals from rust and corrosion that are infused into packaging materials including poly films, paper, emitters, chipboards, desiccants and many other components.
The VCI ions form a shield of protection on the surface of metal that displaces moisture and eradicates rust. VCI Packaging safely prevents corrosion on protected metals without the need for messy grease, oils, protective coatings or other time-consuming methods. How to Prevent Rust in Any Situation In short, the best way to prevent rust is to prevent moisture from reaching the metal, or by using a material that corrodes more slowly.
Use an Alloy: The use of alloys, like stainless steel, is one of the most common ways to prevent rust, or slow it down. Electroless — This method uses a chemical reaction to deposit a coating of metal like nickel or cobalt to the primary metal.
The method doesn't require an electric current to complete. Hot dipping — It's a simple coating technique that requires the substrate to be immersed in a molten bath of protective metal, forming a thin protective layer around the substrate metal. You can either use cathodic protection in a process known as galvanizing or use anodic protection. By controlling the environment, you can prevent or reduce the rate of corrosion. There are both simple and complex methods you can try. The simple ones include reducing exposure to moisture while complex alternatives include controlling the oxygen, sulfur, or chlorine levels in the environment around the metal.
Simple adjustments like avoiding cracks and pits where the metal can hold water or encourage free movement of air can go a long way in preventing corrosion. One of the best ways of preventing corrosion is planning ahead. Having effective corrosion prevention methods can prolong the life of metal and retain the aesthetic appearance.
How to Control Corrosion by Improving Design. Why is Stainless Steel Corrosion Resistant? An Introduction to Hydrogen Embrittlement. An Intro to Pipeline Corrosion in Seawater. Follow Connect with us. Sign up. Thank you for subscribing to our newsletter! Connect with us.
Key Takeaways. Share This Article. Krystal is a civil engineer and project manager with an MSc in Construction Engineering and Management. Her experience includes the project management of major infrastructure projects, construction supervision, and the design of various infrastructure elements including roadway, pavement, traffic safety elements and drainage.
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