The use of iron by man has a long history. Metal ores are fairly widespread. The iron content in the earth's crust is 4.1 percent, that is, by this parameter it is in second place among metals and in fourth among all elements. Therefore, there is nothing surprising in the fact that even before our era (II millennium) a method was found for its production and further processing. Further technologies were improved, new methods for producing iron were discovered, and gradually this metal began to occupy a leading position in material production.
The value of iron is not limited only to the field of material production. It is part of hemoglobin as a microelement - our blood has a red color due to the presence of iron in it. Iron is necessary for the normal growth and development of plants, it takes part in oxidative processes and is part of protoplasm.
Any substance, including iron, has its own characteristics. If you put one kilogram of this metal and one kilogram of fluff on the scales, then their weight will be the same, only the volume will be completely incomparable. The thing is that the density of iron is much higher than that of fluff. Density is understood to mean mass enclosed in unit volume. Each substance has its own density . For water, for example, one thousand kilograms / cubic meter, for ice - nine hundred kilograms / cubic meter.
Density is defined as the ratio of mass to occupied volume. Density is influenced by several factors. So, it depends on the temperature. For many substances, the following relationship applies: with decreasing temperature, the density increases, with increasing it decreases. True, there are several exceptions to this rule, and one of them is water. Here everything is the other way around; as the temperature decreases, its density decreases.
Thanks to such an exception, there is life on Earth. Ice is lighter than water, and it holds onto the surface. Otherwise, he would sink to the bottom, lay there and not melt. And over time, all the seas and oceans would completely freeze. So it turns out that the concept of the density of substances allows us to make an extremely curious conclusion about the possibility of life on Earth.
Density is largely dependent on the chemical composition of the substance. Silicon and carbon have the greatest effect on the density of iron. They lower the density of pure iron, which is 7800 kilograms / cubic meter at room temperature. At the same time, the properties of iron depend on the carbon content. In fact, iron is used in alloys, especially with carbon - in various steels and cast irons.
Cast iron usually contains more than 2.14 percent carbon, the carbon content in steel is lower (0.8-1%). The density of iron in these cases will be different. Solid iron has a density of 7000-7200 kilograms / cubic meter at ordinary temperature, steel under the same conditions has a density of 7500-7600 kilograms / cubic meter. Thus, the density of steel is between cast iron and iron.
According to its characteristics, cast iron is brittle: if you hit it, it breaks. Steel is obtained by processing cast iron in an oxygen converter. With such processing, the carbon content decreases, it is said to burn. In its properties, steel is very different from cast iron. It can be forged and manufactured. Steel acquires additional properties thanks to additives that give it the necessary characteristics - strength, flexibility, hardness.
In the given material, such a concept as the density of iron is considered. The features of changes in the density of certain substances under various environmental conditions are described. The individual properties of iron itself and its significance in material production, as well as a trace element in the body, are examined.