In school, we all came across corrosion and rusting in the syllable of chemistry. But how many of us precisely remember the distinctions? Not many of us. And this we often fail to mark the difference between the two. Corrosion and rusting are similar in some aspects, but they occur on different kinds of surfaces.
Corrosion vs Rusting
The main difference between corrosion and rusting is that corrosion can occur in metal as well as non-metal things but rusting only grab things that are made of steel and iron. Corrosion can also happen to the skin as it is a chemical reaction, but rusting can not have any effect on our skin.
Corrosion cause decay to affected things, but in rusting, only a layer of rust occurs on the surface. Corrosion is the effect of chemical reactions. This process can damage things thoroughly. One should always handle chemicals with care to avoid any unnecessary casualties. The effect of corrosion on metal products can be prevented by putting on a layer of zinc over it.
Rusting is nothing but a type of corrosion. It is an oxidation process that happens in the presence of oxygen and moisture. Rushing only affects steel and iron. But if the steel or iron products obtain a coating of zinc, chromium, or nickel, then the rust can get avoided easily.
Comparison Table Between Corrosion and Rusting
| Parameters of Comparison | Corrosion | Rusting |
| Definition | When a substance deteriorates as the outcome of chemical, electrochemical or other reactions, it is called corrosion. | When iron gets exposed to air and moisture, it gets a coat of orange or red substance, this is called rusting. |
| Reaction surface | Corrosion can take place on wood, skin and even on metal. | It occurs on iron and steel-based surfaces. |
| Reason | Corrosion takes place because of the spread of chemicals on the surface. | Rusting takes place because of revelation to air and moisture. |
| Result | If corrosion takes place on wood then it gets destroyed. If it takes place on the skin then it burns the skin. | If rushing happens then the surface gets covered by the orange coating. |
| Chemicals | The main component of corrosion is chemical reactions. | Chemical reactions do not have any role to play in rusting. |
What is Corrosion?
One form of oxidation is corrosion. It can affect both metallic and non-metallic things. Various chemical reactions are reasons for corrosion. Corrosion is strong enough to decay the structure of the surface. It is capable of burning skin and demolishing wood. Chemicals that contain powerful acids, for instance, HCl, H2SO4, KOH, and NaOH, etc., are highly capable of giving way to a chemical reaction. Such chemicals are called are corrosive chemicals because of their capabilities of causing corrosion. The damage caused by chemicals like this is permanent.
Corrosion is better avoided, and you can cut down the chance of corrosion by taking few measures. One of the most common prevention is galvanization. In this process, the surface gets a layer of zinc over it. This way, no reaction takes place. Painting the surface is also another way to prevent corrosion. You should always handle chemicals carefully to avoid any accident.
What is Rusting?
Rusting is a reaction that takes place on steel or iron-made things. This is a type of corrosion that causes by air and moisture. The oxygen of air takes part in the reaction. That is why it is an oxidation reaction. In rusting, steel and iron comes in touch with moisture and air and therefore develops a layer or coat of rust.
Rust is red or orange, and gradually as the rust keeps on building, the iron and steel surface gets fragile. Rusting does not begin for chemicals, but the things that have had been subjected to rust can react to chemicals and get worse. The amount of rusting on a surface depends on many external factors, for instance, the rate of humidity in the air.
With the help of few preventions, rusting on metals can be avoided. The most common way to resist rust is by getting a coat of zinc over iron and steel. Zinc acts as a sacrificial anode, and it can combat rusting. Electroplating or a coating of chromium or nickel are also good in preventing rusting. Stainless steel is immune from rusting because it contains a coating of chromium.
Main Differences Between Corrosion and Rusting
- Corrosion is the outcome of chemical electrochemical reactions, whereas rusting is a reaction due to exposure to air and moisture.
- Corrosion eradicates things completely but rusting only causes a layer of rust on the substance.
- Corrosion is capable of destroying any type of surfaces such as wood, skin, and metal. On the other hand, rusting only affects things made of iron and steel.
- Corrosion can take place on the skin as well and burn it. But rusting has no effect on the skin.
- Chemical reactions are the main reason for corrosion to take place, but in the case of rust, no chemical reaction is needed.
- Things that have been subjected to corrosion might lose their functionality, but things that have been subjected to rusting can work with mild rust. Gradually when the rusting gets severe, the thing will get useless.
Conclusion
Both corrosion and rusting are oxidation reactions. Corrosion can not take place without the presence of chemicals, but rusting can occur with the exposure of oxygen in the air and moisture. Rusting, in the beginning, does not cause any serious damage, but with corrosion, the subjected surface loses its functionality and structure completely. It deteriorates instantly.
Corrosion is also capable of imposing an impact on our skin. But rusting can not happen to humans as rusting is only limited to things that are made with steel and iron. Although corrosion and rusting are not unavoidable. A layer of other chemicals can prevent the damages due to these reactions.
References
- https://www.tandfonline.com/doi/abs/10.1016/j.stam.2007.08.010
- https://www.tandfonline.com/doi/abs/10.3109/03639048509057681