Ferrous metals are a broad category that includes both pure substances and their alloys. Moreover, it is they who make up the bulk of the global metallurgical industry.
It is customary to refer to the category of ferrous metals, first of all, iron, as well as all kinds of alloys made on its basis. In addition, some experts refer to this group as metals such as manganese and chromium. Substances belonging to this group are usually characterized by a dark gray color, which is the reason for the assignment of this name.
Iron is one of the most abundant metals on earth. This became one of the main reasons why it was iron that formed the basis for determining the group of ferrous metals.
Iron itself is a fairly light, silvery metal. Moreover, this substance can be called unstable: it is extremely easily exposed to the negative effects of external factors, for example, corrosion as a result of oxidation. Moreover, when it enters an environment consisting of pure oxygen, iron tends to ignite. This is due to its high ability to enter into various chemical reactions.
At the same time, however, in its pure form, iron practically does not occur in nature. In addition, due to its chemical and physical properties, the use of pure iron is difficult for industrial, economic and other purposes. Therefore, iron is most often used in the form of various alloys obtained by adding special additives to the pure substance.
Iron based alloys
The ferrous metallurgical industry, producing iron-based metals, occupies about 90% of the world metallurgy. At the same time, the lion's share of all alloys in this category are those in which, along with the iron content in one or another proportion, carbon is present.
Depending on the concentration of carbon in specific alloys, it is customary to subdivide them into two large groups: steels and cast irons. So, if the carbon content in the finished substance is less than 2.14%, we are talking about steel; otherwise, such an alloy belongs to the category of cast irons. Both the one and the other metal, due to the addition of carbon to iron and iron, acquire a sufficiently high degree of strength, however, steel is a ductile metal, and cast iron is brittle. For example, a cast iron product can be shattered if accidentally dropped onto a hard surface.
At the same time, carbon is not the only element that is used to add to iron in the process of obtaining alloys from the category of ferrous metals. So, other options for such additives are manganese, phosphorus, sulfur, silicon and other substances.