Why is iron particularly prone to rust? Why does iron rust easily?

Kitchen knives are left unused for a long time, and their surface tends to be rusty. Iron is prone to rust, mainly due to its nature. Iron is a relatively reactive metal, which means that it can easily react chemically with other substances.

In a humid environment, iron rusts easily; Conversely, iron is less susceptible to rust in dry conditions. There is oxygen in the air, and iron will undergo a chemical reaction when it encounters oxygen, and the main component of rust is iron oxide formed after the reaction of iron and oxygen.

The main causes of iron rust are air oxidation and electrochemical corrosion. As a result of an oxidation reaction with oxygen in the air, metal oxides, known as rust, are formed on the surface. If the metal contains more impurities, these impurities will form a chemical galvanic battery with the metal, and electrochemical corrosion will occur, thereby oxidizing the metal to form metal oxides.

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Among the metals, aluminum has one of the strongest corrosion resistance, and aluminum and iron are compared.

Unlike aluminum, iron reacts chemically with oxygen and water in the air to form hydrated iron oxides (III), but these hydrated iron oxides (III) do not adhere firmly to the surface of the iron, so if the rusted iron is gently scraped, the rust will peel off, causing the new iron surface to be exposed to air and water. As a result, rust continues to circulate through the surface of the iron, causing the iron to break structurally.

But aluminum is different, when aluminum reacts with oxygen and water in the air, it will form alumina (II), alumina is very reliable, can effectively adhere to the surface of aluminum, prevent air and water from continuing to invade the interior of aluminum, so aluminum windows will not rust for five or six years, so aluminum can effectively resist rust.

Because iron reacts with oxygen and water vapor at room temperature, iron oxide, also known as rust, is formed. However, ferric oxide is not dense and cannot protect the inner layer of iron, so the inner layer of iron will also react with oxygen and water vapor in the air to form rust, and eventually the whole piece of iron will corrode away.

The key is not whether the iron is easy to oxidize, but its oxidation product - the iron oxide structure is very loose, which cannot protect the unoxidized part of the lower part, causing the lower part of the iron to continue to be oxidized! Like aluminum and stainless steel are completely different, alumina is very dense and has the effect of protecting the lower part of aluminum from oxidation, and chromium in stainless steel also has the same effect.

Due to the nature of iron itself, and the environment in which iron is produced, if it is in humid air, it must be easy to rust in a drier place.

Because iron undergoes a chemical reaction in the air to "oxidize", you will learn it physically.

As the saying goes: "A quick knife doesn't need to be yellow and rusty".

Iron, indeed, is prone to rust. Every year, tens of millions of tons of steel in the world turn into rust.

Iron is susceptible to rust, not only because of its chemical activity, but also because of its external conditions. Moisture is one of the conditions that makes iron rust easily. Chemists have proven that in absolutely waterless air, iron does not rust after a few years.

However, the presence of water alone does not rust iron. It has been experimented with when a piece of iron is placed in a boiled, airtight bottle of distilled water, and the iron does not rust.

Do you notice those water pipes along the river? They are often rustless at the top and stainless at the bottom, and it is only the section near the surface that rusts.

It turns out that iron rusts only when the oxygen in the air is dissolved in the water. The part close to the surface of the water is the closest to the air, and the water dissolves the most oxygen, so it is easy to rust. Carbon dioxide in the air dissolves in water, which can also rust iron.

The composition of rust is very complex, mainly iron oxide, iron hydroxide and basic iron carbonate.

How do you protect steel? The most common way to prevent rust is to put "clothes" on iron.

The surface of the iron is painted or plated with other metal that does not rust easily. For example, a car is dressed in shiny spray paint; The heating pipes are painted with aluminium; The tinplate used for canning is plated with a layer of tin; The white iron sheet on the roof is zinc-plated.

A more radical approach is to inject iron with a "booster" – adding other metals to make a stainless alloy. The famous stainless steel is an alloy made by adding a little nickel and chromium to the steel.

Iron rusts when left for a long time. Iron is susceptible to rust, not only because of its chemical activity, but also because of external conditions. Moisture is one of the substances that makes iron rust easily.

However, the presence of water alone does not rust iron, and only when the oxygen in the air is dissolved in the water, the oxygen reacts with the iron in the presence of water to form something called iron oxide, which is rust. Rust is a brownish-red substance, it is not as hard as iron, it can easily fall off, and after a piece of iron is completely rusted, the volume can expand by 8 times. If the rust is not removed, the spongy rust is particularly easy to absorb water, and the iron will rot faster.

To remove rust, you can shovel it off with various tools or soak it in an acidic solution to dissolve it. After removing the rust, the surface of the iron must be treated, coated with a layer of lead, and then painted; Or plating it with other metals that don't rust easily. A more radical approach is to add some other metals to the iron to make a stainless alloy.

The stainless steel we are familiar with is an alloy made by adding a little nickel and chromium to the steel.

Do you know why iron rusts?

Because iron and water have a chemical reaction to form iron oxide. The most common way to prevent rust is to put "clothes" on iron. The surface of the iron is painted or plated with other metal that does not rust easily.

The susceptibility of iron to rust is mainly determined by the nature of iron, which is a relatively reactive metal that can easily react with other substances. In a humid environment, iron rusts easily; The necessary condition for iron to rust is the presence of oxygen and water at the same time.

In the presence of salt, the rust will deepen and the speed will increase. Once the iron is rusty, it will cause some damage to the item, making the item less beautiful and delicate.

How to preserve ironwork.

Keep the surface of iron products clean and dry, such as drying kitchen knives when not in use; Paint the surface of steel by covering it with a protective film, such as the surface of a car or a ship.

Plating a layer of other metals on the steel watch, such as chrome plating and galvanizing on the surface of the faucet; Structures made of good metal, such as stainless steel.

Go to the brigade to remove rust method.

Heat the iron first, then dip a towel in vinegar and apply it to the rusty area so that the rust will fall; Soak the rusty iron in thick rice washing water for three or four hours, then boil the rice washing water, put the iron into the rice washing water and stir in the process, and finally rinse it with clean water.

Iron rollers are prone to rust, in addition to its chemical activity, and at the same time have a lot to do with external conditions. Moisture is one of the conditions for making iron rust. Chemists prove:

Iron is placed in absolutely waterless air, and it does not rust for several years. However, the presence of water alone does not rust iron. If a piece of iron is placed in a boiled, airtight bottle of distilled water, the iron will not rust.

It is only when oxygen acts at the same time as water that the iron rusts. In addition, carbon dioxide in the air dissolves in water, which can also cause iron to rust. The composition of rust is very complex, mainly iron oxide, iron hydroxide and basic iron carbonate.

The rust is loose and soft, like a sponge, and after a piece of iron is completely rusted, the volume can expand by 8 times. Spongy rust is particularly easy to absorb moisture, which makes the iron rot faster.

There are also many factors that make iron easy to rust, such as salt in water, the surface of iron products is not clean and rough, and iron contains impurities such as carbon.

Do you know why iron rusts?