Steel


Steel is a metal that is derived from the alloy between iron and carbon. It is characterized by its resistance and because it can be worked hot, that is, only in the liquid state. Well, once it hardens, its handling is almost impossible. As for the two elements that make up steel (iron and carbon), they are found in nature, which is why it is positive when it is produced on a large scale.

What is steel

Steel is basically an alloy or combination of iron and carbon, it is basically highly refined iron (more than 98%), its manufacture begins with the reduction of iron (pig iron production) which then becomes the named metal. It refers to the element from which edged weapons were made in ancient times, which in its etymology this word is composed of the Latin «aciarĭum», from «acĭes» or filo and in turn from the Greek «akē» which means tip.

Steel history

The date when the technique of smelting iron ore was discovered was not exactly known, however, the Greeks through heat treatment, hardened iron weapons, this was in the year 1,000 BC.

The first artisans to work iron produced alloys that today would be classified as wrought iron, this was done through a technique that consisted of heating a mineral mass of iron and coal that was mixed in a large furnace with forced draft. The way was that the ore was reduced to a mass of metallic iron filled with slag, that is, metallic impurities, together with coal ash.

This mass of iron was worked while remaining red hot, hitting it hard with heavy hammers in order to expel the slag. Occasionally, this manufacturing technique accidentally produced real steel instead of wrought iron.

Then, from the fourteenth century on, the size of the furnaces for smelting iron increased considerably. In these larger furnaces, the iron ore from the top of the furnace was reduced to metallic iron and then absorbed more carbon as a conclusion of the gases, the product of these furnaces was called pig iron, this is the first process to obtain the element .

Later, Carl Wilhelm Siemens in 1857 created a method, in which the metal could be made based on the decarburization of the utility of iron or iron oxide as a product of heating.

In 1865, steels with 25% and 35% nickel were already made in very limited quantities, which resisted much better the action of humidity in the air, however they were very small-scale producers. Since then, and until the year 1900, alloys with chromium were studied, which improved the corrosion resistance of steel.

Later on, numerous studies were carried out on alloys with chromium and nickel, that is when it can be said that the stainless steel that we know today appears.

Thus, stainless is not a simple metal, but an alloy, whose main material is iron, to which a small proportion of carbon is added. Thus a solid material is achieved and resistant to external agents that can deteriorate it.

Today, stainless steel has a multitude of applications and surrounds us in practically all areas of our life, but it also has a great presence in the industrial field, being a very important part of the equipment of pharmaceutical, petrochemical, and industrial plants. treatment of liquids, tanks. containers, among many others.

Steel characteristics

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Steel has important and essential properties that allow it to be used by the automotive industry, in the construction of houses and in an infinite number of elements. Among its essential characteristics are:

Components (edit)

As for the steel composition, iron and other elements such as carbon, manganese, phosphorus, nickel, sulfur, chromium and more are basic. Variations in composition are responsible for a wide variety of grades and properties.

Density

Its average density is 7850 kg / m³. Depending on the temperature, it can contract, expand or melt. The melting point depends on the type of alloy and the percentages of alloying elements.

Corrosion

There is corrosion and wear due to continuous exposure to climatic or external factors that cause alterations to the electrical composition of the material and thus deteriorate the molecules and particles.

Conductivity

It has a high electrical conductivity. Although it depends on its composition, it is approximately 3 · 106 S / m.

Steel types

This has many applications in the daily life of people, since it is common in utensils, tools and appliances, as well as in the structures of modern homes and buildings, it all depends on its type:

Galvanized steel

It is the result of combining the mechanical resistance properties of metal and the anticorrosive properties of zinc. This type is used for construction, the manufacture of large structures, in communication, electricity and transportation.

Stainless steel

It is the kind that is molded, composed of chromium and nickel, which make it shiny and resistant to corrosion even when it is exposed to humidity.

Construction steel

First the crude iron ore is crushed and classified. Charged in a blast furnace, the resulting reaction begins to remove impurities. It is extracted and heated even more to allow the inclusion of other substances, such as manganese, which will give different properties to the finished product.

Calm steel

This type is completely deoxidized before casting, by adding metals.

Forged steel

It is this that has been modified in shape and internal structure, through the application of forging techniques carried out at a temperature higher than that of recrystallization. It has less surface porosity, a finer grain structure, more tensile and fatigue strength, and more ductility than any other processing.

Rolled steel

It is one that has passed through rollers at very high temperatures, over 1,700 ° F, which exceeds the recrystallization temperature of most metal. This makes it easier to mold and results in products that are easier to work with.

Steel applications

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It is assured that this material is of utmost importance in human function, since no other combines its properties such as: resistance, plasticity and versatility.

However, the uses of steel prevail in the construction of machinery, tools, utensils, mechanical equipment, electrical appliances and in structures of homes, buildings and public works. Also included are railway construction companies and rolling stock. For use in construction, it is distributed in metal profiles that have different characteristics depending on their shape and size, specifically used in steel beams or pillars.

Corrugated is also a rolled type that is used for reinforced concrete structures. They are bars of different diameters that have projections. It is used in structures, insulation, cladding, mezzanines, roofs and finishes. Its use is essential due to its greater resistance, it does not contract or deform. More resistant than other materials in earthquakes, wind and fire, which makes this type of construction much safer.

It should be noted that there is a symbol steel linked to specific characteristics for the production of different products. Therefore, for metallic construction they are designated with an S (steel) followed by a number that indicates the minimum specified value of the elastic limit in MPa (1 MPa = 1N / mm2), for the thickness interval plus little. Additional symbols are divided into group 1 and group 2. If the symbols in group 1 are insufficient to fully describe, additional symbols can be added in group 2. Symbols in group 2 should only be used in conjunction with those in group 1 and should be behind them. Example: S355xyz (additional symbol).

Frequently Asked Questions about Steel

What is steel?

It is the mixture of a metal such as iron and a metalloid such as carbon, which can appear in different proportions but never more than two percent of the total weight of the final product.

What metals does steel contain?

The metals that the element contains are:

  • Aluminum
  • Boron
  • Cobalt
  • Chrome
  • Tin
  • Manganese
  • Molybdenum
  • Nickel
  • Lead
  • Silicon
  • Titanium
  • Tungsten or tungsten
  • Vanadium
  • Zinc

What is steel for?

Steel production is used for houses, steel plate to reinforce buildings, facades, etc. Likewise, in the heavy weapons and armored vehicles industry. In the manufacture of tools, utensils, mechanical equipment, industrial machines and agricultural machinery. The automotive industry, crankshaft, gearbox drive shafts, among other industries.

What are the types of steel?

There are a variety of types, which are:

  • Cut
  • Afraid
  • Corrugated
  • Galvanized
  • Stainless
  • Laminate
  • Carbon
  • Alloy
  • Sweet
  • Effervescent
  • Cold Drawn
  • Structural
  • Weathered
  • Gentle
  • Black

How is steel obtained?

Iron is melted in a furnace, poured to reduce impurities. Then 99% pure oxygen is injected. The lime is mixed to form a residue that absorbs the remaining impurities. Finally it is refined in a furnace adding alloy products to give the desired properties.