Different types of iron and its material properties


This article gives an overview of different types of Iron which includes wrought iron, white cast iron, grey cast iron, malleable cast iron, and nodular cast iron. Each iron is classified based on its physical and chemical properties with respect to carbon percentage and its application.

In everyday life, we often come across many types of structures made up of iron and its alloy. Iron is one of the most used material in the world and one needs to use it in everyday life in terms of many structures, appliances, and other ways. This article shows you how many types of Iron, engineers are using in applications based on their properties and suitability.

Different types of iron and its material properties

Pig Iron and its properties

  • Pig Iron is a basic raw material for all irons and produced from a blast furnace.
  • It contains Carbon percentage equal to 3-4%
  • Pig Iron from ore contains three basic forms, namely cast iron, wrought iron and steel.

    Cast Iron and its properties

    Cast iron is an alloy of iron having a carbon percentage of more than 2 % and is made from a Cupola furnace. It is available in various forms namely malleable cast iron, nodular cast iron or ductile cast iron, gray cast iron, and white cast iron. Cast iron is brittle in nature and can break if it is suddenly struck with a hammer or dropped from a height.

    Malleable Cast Iron and its properties

    • Malleable Cast Iron is obtained from hard & brittle white iron., through a controlled heat treatment conversion process.
    • Malleable Cast Iron is having Carbon percentage: of 2 % to 3 %
    • Malleable Cast Iron has material properties like High yield strength, ease of machinability, corrosion resistance, and high young modulus
    • It is having a low coefficient of thermal expansion and high wear resistance & damping vibration.
    • Shrinkage Allowance for this Iron is 1.5 mm / 100mm
    • Malleable Cast Iron is used to make Crank-shaft, railroad, universal joint etc.

    Nodular cast iron (most ductile cast iron) and its properties

    • Nodular cast Iron contains Carbon % : 3.2 % & 4.2 %
    • Nodular cast Iron is having damping capacity intermediate between cast iron & steel.
    • This iron is also having high wear resistance
    • Application: Pump compressor, valve, i.c engines, pipe, paper industry, earthmoving machinery.

    Grey cast iron and its properties

    Grey cast iron can also be produced from pig iron. Grey cast iron is named from the color of its microstructure, and because of graphite/silicon, it is grey in color. Graphite also contains self-damping capacity and is oft in strength. Other things to know-
    • Grey Cast Iron is an alloy of Carbon & silicon with iron.
    • Carbon percentage of Grey Cast Iron: 2.5 to 3.8 %
    • Grey cast iron is having Self-damping, good anti-friction properties and also has the lowest melting point. This is the reason why grey cast iron is mostly used in machining beds (lathe machine, milling machine) to reduce and absorb the vibration due to self-damping properties.
    • Applications of Grey Cast Iron: Machine tool structure, manhole covers, piston rings, rolling mill. Water pipes.

    White cast iron and its properties

    • Carbon % of White Cast Iron : 1.8 % to 3.6 %
    • White Cast Iron is not machinable
    • Shrinkage allowance for this type of Cast Iron is 1 mm/ 100 mm

    Wrought Iron and its properties

    Wrought Iron is also an alloy of iron with a very less carbon percentage around 0.08 % compared to cast iron. "Wrought" means 'it is worked on. Thus, wrought iron is actually a worked iron. Wrought iron is not as brittle as cast iron. Wrought iron is prepared with the puddling process in a puddling furnace. Other facts-
    • Wrought Iron is a mechanical mixture of pure iron and silicate slag
    • Its Carbon percentage is 0.02% to 0.03%
    • Wrought Iron is never cast or difficult to cast
    • Wrought Iron is having high ductile, corrosion-resistant, fatigue resistant
    • It is having Tensile strength: 3380-3500 kg per square centimetre and 2530-2670 kg per square centimetre in a transverse direction
    • Wrought Iron's melting point: 1510 degree C, Weight – 7680 kg per meter cube.
    • Wrought Iron's Poisson's ratio: 0.3
    • Wrought iron is used to make cooking pan, wire ropes, staircase grills, fences, gates, railing etc.

    Steel and its properties

    Steel which is made from the Bessemer converter is also an alloy of iron having a very fewer percentage of carbon. This increases the fracture resistance and strength of steel.
  • Steel is having many forms namely carbon steel, spring steel, alloy steel, high-speed steel, stainless steel, tool steel, etc,
  • Steel is having good thermal conductivity compared to cast iron and other forms of iron.

  • Each steel type is having its unique properties.
  • Carbon steel is having carbon percentage vary from 0.05 to 2.
  • Carbon steel literally means that it is not stainless steel.
  • Carbon steel is widely used in automobile axels, gears, rails, shafts, pipelines etc,.
  • Spring carbon steel is used to manufacture springs, swords, piano wires, knives, binder clips, saw blades, etc,.
  • Alloy steel is a steel having different alloying elements added to increase the desirable properties for an application. The percentage of alloying element decides the properties of that steel
  • stainless steel contain 11% chromium and this enables it to form stain, corrosion, or rust resistance
  • The high-speed steel is used to prepare cutting tools for machining operations
  • tool steel is used to manufacture dies, knives, hammers, chisels etc.

  • Why is iron a magnetic metal?

    Metals like nickel, iron, cobalt, gadolinium, etc. are having four free electrons having the same spin directions. This enables them to be magnetic compared to the other metals.

    Conclusion

    If we conclude, that iron is having basic three types namely pig iron, cast iron, and wrought iron. Iron is magnetic material because its free electrons have the same spin directions. The other properties of iron depend on the amount of carbon it contains.


    Comments

    Guest Author: Ashwani Ranjan28 Sep 2014

    It was quite helpful to understand basic iron types.

    Guest Author: Bhavin parmar11 Mar 2015

    Yeah this website is so helpful for me
    Because I am weak in metal information.
    So it gives me some meaningful information for my studies.
    I like it
    Please can you send me mail of many different. Types of metal and material properties

    Guest Author: Ankita das01 Apr 2015

    Can u please explain the difference between types of iron and alloys of iron?
    I'd there any difference?

    Guest Author: karthik21 Jun 2015

    I want more information about iron and their properties

    Guest Author: krishna04 Jul 2015

    Very nice and easy to understand

    Guest Author: TANKI JOHN MONERI14 Dec 2017

    I need information on their pros and cons based on how they are used.

    Guest Author: Shankar Dey15 Apr 2019

    This article was quite helpful to understand basic types of iron.



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