What is a Steel and its Composition?

What is a Steel?

Steel is an alloy of iron with typically a few percent of carbon to improve its strength and fracture resistance compared to iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant need typically an additional 11% chromium.

Steel Composition: Steel is an alloy of iron and carbon containing less than 2% carbon and 1% manganese and small amounts of silicon, phosphorus, Sulphur and oxygen. Steel is the world’s most important engineering and construction material. It is used in every aspect of our lives; in cars and construction products, refrigerators and washing machines, cargo ships and surgical scalpels.

The main reasons for the popularity of steel are the relatively low cost of making, forming, and processing it, the abundance of its two raw materials (iron ore and scrap), and its unparalleled range of mechanical properties.

The most important properties of steel are great formability and durability, good tensile and yield strength and good thermal conductivity. As well as these important properties the most characteristic of the stainless-steel properties is its resistance to corrosion.

The physical properties of steel include: high strength, low weight, durability, ductility and corrosive resistance. Steel offers great strength, even though it is light in weight. In fact, the ratio of strength to weight for steel is lower than any other building material.

The Chemical properties of steel include: Steel has a density of 7,850 kg/m3, making it 7.85 times as dense as water. Its melting point of 1,510 C is higher than that of most metals. In comparison, the melting point of bronze is 1,040 C, that of copper is 1,083 C, that of cast iron is 1,300 C, and that of nickel is 1,453 C.

Steel

Types of Steel

Steel can be categorized into four basic groups based on the chemical compositions:

  1. Carbon Steel
  2. Alloy Steel
  3. Stainless Steel
  4. Tool Steel

There are many different grades of steel that encompass varied properties. These properties can be physical, chemical and environmental. All steel is composed of iron and carbon. It is the amount of carbon, and the additional alloys that determine the properties of each grade.

Carbon Steel

Carbon steel looks dull, matte-like, and is known to be vulnerable to corrosion. Overall, there are three subtypes to this one: low, medium, and high carbon steel, with low containing about .30% of carbon, medium .60%, and high 1.5%. The name itself actually comes from the reality that they contain a very small amount of other alloying elements. They are exceptionally strong, which is why they are often used to make things like knives, high-tension wires, automotive parts, and other similar items.

Alloy Steel

Next up is alloy steel, which is a mixture of several different metals, like nickel, copper, and aluminum. These tend to be more on the cheaper side, more resistant to corrosion and are favored for some car parts, pipelines, ship hulls, and mechanical projects. For this one, the strength depends on the concentration of the elements that it contains.

Tool Steel

Tool steel is famous for being hard and both heat and scrape resistant. The name is derived from the fact that they are very commonly used to make metal tools, like hammers. For these, they are made up of things like cobalt, molybdenum, and tungsten, and that is the underlying reason why tool steel has such advanced durability and heat resistance features.

Stainless Steel

Last but not least, stainless steels are probably the most well-known type on the market. This type is shiny and generally has around 10 to 20% chromium, which is their main alloying element. With this combination, it allows the steel to be resistant to corrosion and very easily molded into varying shapes. Because of their easy manipulation, flexibility, and quality, stainless steel can be found in surgical equipment, home applications, silverware, and even implemented as exterior cladding for commercial/ industrial buildings.

Uses of Steel

Iron and steel are used widely in the construction of roads, railways, other infrastructure, appliances, and buildings. Most large modern structures, such as stadiums and skyscrapers, bridges, and airports, are supported by a steel skeleton. Even those with a concrete structure employ steel for reinforcing.

Some Uses of steels is given below:

  1. Steel is environment-friendly & sustainable. It possesses great durability.
  2. Compared to other materials, steel requires a low amount of energy to produce lightweight steel construction.
  3. Steel is the world’s most recycled material which can be recycled very easily. Its unique magnetic properties make it an easy material to recover from stream to be recycled.
  4. Steel can be designed into various forms. It gives better shape and edge than iron which is used to make weapons. 
  5. Engineering steels are used for general engineering and manufacturing sectors. 
  6. Steel is highly used in the automobile industry. Different types of steels are used in a car body, doors, engine, suspension, and interior. The average 50% of a car is made of steel.
  7. Steel reduces CO2 emissions.
  8. All types of energy sectors demand steel for infrastructure and resource extraction. 
  9. Stainless steels are used to produce offshore platforms and pipelines. 
  10. Steels are used for packaging and protecting goods from water, air and light exposure. 
  11. Most of the household appliances like fridge, TV, oven, sinks, etc are made of steel. 
  12. Steels are used for producing industrial goodies like farm vehicles and machines.
  13. Stainless steel is used as a cutlery material.
  14. Because of its easily welding capability and attractive finishing, steel has become a prominent feature in modern architecture.
  15. Stainless steel gives a hygienic environment. That’s why it is used for surgical implants.
  16. Steel has a wider range of temperature which is used to make large sheets. 
  17. Renewable energy resources like solar, hydro and wind power use the stainless-steel components. 
  18. Mild steel is used for building construction. It is also a highly favored building frame material.

Top Ask Questions

Steel is an alloy of iron with typically a few percent of carbon to improve its strength and fracture resistance compared to iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant need typically an additional 11% chromium.

Steel is an alloy of iron and carbon containing less than 2% carbon and 1% manganese and small amounts of silicon, phosphorus, sulphur and oxygen. Steel is the world’s most important engineering and construction material.

The properties that need to be considered by designers when specifying steel construction products are:

  1. Strength.
  2. Toughness.
  3. Ductility.
  4. Weldability.
  5. Durability.

The Four Main Types of Steel

  1. Carbon Steel
  2. Alloy Steel
  3. Tool Steel
  4. Stainless Steel

Iron and steel are used widely in the construction of roads, railways, other infrastructure, appliances, and buildings. Most large modern structures, such as stadiums and skyscrapers, bridges, and airports, are supported by a steel skeleton. Even those with a concrete structure employ steel for reinforcing.

Your Replay is valuable for us!!!!