Difference between Alloy and Steel

Key Difference: An alloy is a blend consisting of metal and other elements. Alloys are generally made for achieving properties like greater strength or resistance to corrosion. Steel is an alloy of iron. It mainly consists of iron with some small amounts of carbon.

Alloys are made by the combination of two or more metals. However, in some alloys, a metal is also blended with a non-metal. Thus alloys are not pure elements, and therefore are known as blends. These alloys are made in such a way that it is not possible to separate them into their original constituents by physical means. Currently, most of the metals are used in their alloy form.

It is important to mention that an alloy tends to possess characteristics distinguished from its components. An alloy is formed for gaining better properties than the constituent elements. Most of the times these alloys are designed for getting specific resistances to factors like wear, fatigue, temperature, etc. Nickel and cobalt are blended to form super alloys which are used in aircraft engines. These alloys are highly corrosion and heat resistance.

Alloys are made by using techniques like fusion, reduction and many more. In fusion, the alloying components are melted and then fused. In reduction method, naturally occurring compounds are reduced in an electric arc furnace to get the metal.

Steel is also an example of an alloy of iron. It is made by the combination of iron and carbon. It generally contains less than 2 percent of carbon and 1 percent manganese. The original crystal lattice of iron distorts due to the addition of the carbon. These distortions lead to increase in the mechanical strength of the final product.

For example – stainless steel is made by the combination of elements chromium, nickel and molybdenum, which makes it more resistant for use. Steel may also have some other elements part from iron and carbon but in a very small quantity and that too for achieving some unique properties to steel. Steel has a shiny luster on it. Due to its attractive finish it is used in cutlery and architecture. It has the ability to transfer heat and electricity. It is also known for its strength and resistance to fracture.

Steel is made by using two basic methods – Integrated and Electric arc furnace. In Integrated method, scraping techniques and raw materials are used to create steel. Electric arc furnace uses recycled steel and then it is re-melted. There are some other methods too.

Therefore, steel and alloys are closely related. Steel is an important alloy of iron which is known for its numerous application areas..

Comparison between Alloy and Steel:

	Alloy	Steel
Definition	A homogeneous mixture of a metal with other types of elements	It is an alloy consisting of iron and carbon. It may also contain some other elements too apart from carbon and iron
Example	Brass (copper and zinc) and Bronze (copper and tin)	Stainless steel containing 0.4 percent carbon, 18 percent chromium, and 1 percent nickel
Types	Substitutional Alloy – some of the main metal atoms are substituted by other metal atoms of same size Interstitial Alloy – some of the holes in the closed packed metal structure are occupied by small atoms	Mild steel – it contains upto 0.25 percentage of carbon Medium carbon steel – it contain 0.25 to 0.45 percentage of carbon High carbon steel – it contain s 0.45 to 1.50 percentage of carbon
Naturally occurring	Most of the alloys are made artificially. However, some metals like electrum (alloy of gold and silver) occurs naturally	No. Steel is made in the steel mills which are located in many parts of the world
Some Uses/Importance	Aluminum alloys are mainly used in the production of cars and engine components Copper alloys are known for their thermal performance and high ductility. Nickel alloys are known for their corrosion resistance and heat resistance .Stainless Steel alloys are used in various commercial applications like cutlery, making tubes, etc. Titanium alloys are known for their toughness and therefore are made for construction of aerospace structures	Steel ropes are used in suspension bridges. Steel bars are usually used for various engineering purposes. It is used in the production of gears, electrical motors, power generation related appliances, etc. Modern buildings make use of steel, as it gives a range of versatility in designs It is also used in the production of hulls of ships. Many domestic appliances are made of steel or are coated with steel The bodies of cars are also made from cold reduced steel sheet