The occurrence of rusting is, in reality, far more widespread than most people think. It's not just motorized vehicles that are affected, but in fact, plenty of things. In addition to that, it's not the only metal-based things that may rust, but also other metallic things, as an example, several tools from your toolshed that you may use, for example, garden shears, tap wrenches, and your garden rake. This is the reason why it is important to eliminate rust from your business facilities, this article will guide you on how to easily do that.
The rusting of metal is a natural process that might be sudden or gradual, depending on its material. Perhaps the process is quick if the metal is exposed to moisture or is gentle, taking place over some time.
Other times, rust or corrosion can cause severe problems for the owners of the product.
Rust can cause severe damage to any building. The cost of repairing this damage can be substantial. It can end up costing millions of naira to repair building damage that is caused by rust. This article will look at the cost of rust damage and some of the damage it can cause.
- An introduction to rust and its different forms.
- The cost of rust.
- How to prevent corrosion
Introduction to Rust
Rust is a form of corrosion that involves iron or steel. As the name implies, rust is the oxidization or corrosion of iron or steel that results in various compounds that give the metal a reddish or brownish color. Rust makes metal brittle. The rust affects the appearance of the metal. Rust is an example of a destructive and natural process.
The rusting process is a common problem in all countries. Many objects are exposed to the weather (iron, steel, zinc, etc.), and as a result, they are covered with a oxide layers. The rusting process is a complex chemical process in which oxygen is absorbed by iron under the influence of water and other factors that promote oxidation. The corrosion causes destruction of the metal surface and the formation of corrosion products. If the decay is not stopped, it can destroy the entire object or valuable facility.
The cost of a rust
Global cost of corrosion is estimated to be US$2.5 trillion, which is equivalent to 3.4% of the global GDP (2013). if we use control practices, it is estimated that we could realize savings of between 15 and 35% of the cost of corrosion, this is typically between US$375 and $875 billion annually on a global basis. The above costs does not include other individual safety and environmental consequences. Others are near misses, incidents, forced shutdowns (outages), accidents, etc. Many industries have realized that lack of corrosion management can be very costly and that, through proper corrosion management, they can achieve significant cost savings over the assets lifetime. To achieve some of these savings, organizations must engage in corrosion management and its integrate it into its management system. This can be accomplished by implementing a Corrosion Management System or (CMS).
While high-risk sectors, such as the aerospace, marine, oil, gas, and petrochemical industries, recognize the critical nature of the problem, governments and other sectors have tended to treat corrosion as a repair and maintenance issue. However, a growing realization is that addressing corrosion control in the design stage will ultimately save money over longer substrate lifetimes. A 2002 study of the cost of corrosion in the US revealed that roughly one-third of corrosion costs could be eliminated by proper material selection and protection and adopting a preventive approach.1
We can control corrosion actively or passively. Active protection involves influencing the reactions involved in corrosion, such as cathodic protection, whereby a sacrificial material, often zinc, participates in the corrosion reaction rather than the substrate. Passive protection generally involves applying a film or coating that prevents moisture and other corrosive reactants from reaching the substrate. Corrosion inhibitors are often also formulated into these systems.
How to prevent corrosion
Choice of Metal use
The use of aluminum and stainless steel is the most abundant and cheapest form of preventing corrosion in any facility. Depending on the application, stainless steel and aluminium can be used to reduce the need for additional corrosion protection.
Use of Protective Coatings on use-metals
After fabrication using steel or any metal that is vulnerable to rusting, applying protective coatings to a properly prepared metal surface will do the magic of protecting the metal from rust. It is essential to use appropriate coatings as prescribed by the specialists. anticorrosion paints can act as a barrier to prevent electrochemical charge transfer from the corrosive solution to the metal underneath. Depending on the costs and the relative abundance, powder coating is also a good choice. We powder coating is in use, the powder is applied to a clean metal surface. it is exposed to heat and makes the powder fused into a smooth, unbroken film. Different types of powder coating can be used, acrylic, polyester, epoxy, nylon, and urethane.
Environmental location of the facility
We know that corrosion is caused by a chemical reaction between the metal and oxygen in the surrounding environment. Controlling the environment can help to provide mitigate or avoid these unwanted reactions. We can reduce exposure to rain or seawater or manage sulfur, chlorine, or oxygen in the surrounding environment. Water treatment is the process where water is soften with softeners to adjust the hardness of the water, alkalinity, or oxygen conctent of the water. Treated water are often used in boilers for inductrial applications.
Sacrificial protection using coating
Sacrificial protection using coating is a method of corrosion protection where a thin layer of metal with a lower electrode potential values (having higher levels in the electrochemical series) is used to build a clear barrier or coat on the surface of the metal being protected. This extra layer prevents the metal undeaneth from oxidizing and this is why it is called "sacrifical coating". The two main techniques to achieve sacrificial coating are by using cathodic protection or anodic protection.
Sacrifical coating using cathodic Protection
Sacrificial anode-based cathodic protection when two or more metals are galvanically coupled is a potent electrochemical protection method, an example of cathodic protection is the coating of iron alloy steel with zinc, and the process is known as galvanizing. Steel is a less active metal than zinc, and when zinc starts to rust, its oxides inhibit the steel's corrosion.
Cathodic protection is used in steel pipelines carrying fuel or water, other locations likely using cathodic protection is in water heater tanks, ship hulls and oil platforms that is located offshore. In cathodic protection the steel is used as the cathod of an electrical cell
Sacrifical coating using anodic Protection
The process of anodic protection involves coating the iron alloy steel with Tin, which is a less active metal. Tin will not rust, Steel will not corrode as long as the tin that coats it is in place. In this procedure the steel is made as the anode of an electrochemical cell hence it is called anodic protection. Locations where anodic protection is popularly applied are carbon steel storage tanks used as storage for sulphuric acid and caustic soda, in this enviroment cathodic protection is not a viable preference because of the extremely high current requirments.
Using Corrosion Inhibitors
Corrosion inhibitors have widespread application in suppressing or at least mitigating the corrosion process of metals in different fields, spanning from industrial sectors to construction materials to surface treatments for cultural heritage. Corrosion inhibitors are chemical substance that when present in the corrosion system at a suitable concentration decreases the corrosion rate, without significantly changing the concentration of any corrosive agent.”
Corrosion inhibitors work by applying it to the surface of metal to form a protective coating. One commonly available corrosion protection liquid is epochem 109 corrosion inhibitor. Another way of applying corrosion inhibitors is a process known as passivation.
Passivation is a widely-used metal finishing process to prevent corrosion. In stainless steel, the passivation process uses nitric acid or citric acid to remove free iron from the surface. The chemical treatment leads to a protective oxide layer that is less likely to chemically react with air and cause corrosion.
In passivation, a light coat of protective material, such as a metal oxide, helps to creates a protective layer over the metal, and then it will act as the barrier against corrosion. The protective coat is hence affected by environmental pH, temperature, and surrounding chemical composition. Other essential uses of Corrosion inhibitors are in petroleum refining, chemical production, and water treatment works.
Modify your construction design
Another method to mitigate metal corrosion and increase its durability is by modifying the design. Some design modifications can help to improve the lifespan of the existing anti rusting coatings, for example, an ideal design should avoid situations to trap water or dust, encourage sufficient air movement and avoid open crevices. Designs that ensure metals are exposed for easy maintenance in the future will help increase the lifespan of the facility.