What is Ferrite in Steel Materials?

What is Ferrite in in Steel Materials?

Ferrite is a term commonly used in the field of metallurgy, but many people may not be familiar with its specific definition and properties.

In metallurgy, ferrite refers to the constituent phase of steel or cast iron that has a body-centered cubic (BCC) crystal lattice structure.

Ferrite is often found in low-carbon steels, which have less carbon content than other types of steel.

Ferrite is a type of iron in a crystalline form that has low carbon content, making it soft and ductile compared to other types of iron forms (such as pearlite, cementite or austenite). Ferrite is also known as alpha iron (α-Fe), and it exists at room temperature in the body-centered cubic (BCC) crystal structure.

Ferrite in Fe-C Phase diagram

Ferrite is a type of iron that contains very low levels of carbon, typically less than 0.025%. It is commonly found in steels and other alloys, and it plays an important role in the Fe-C phase diagram. This diagram shows the different phases of iron-carbon alloys at various temperatures and carbon concentrations.

Ferrite (α-ferrite) forms when iron cools below its austenitic phase transition temperature, which occurs at around 911°C for pure iron. As the temperature decreases, the solubility of carbon in ferrite decreases until it reaches a point where further cooling causes excess carbon to precipitate as cementite or other carbides as shown in below phase diagram.


As carbon content increases, other phases begin to appear on the diagram, including pearlite (a mixture of ferrite and cementite), martensite (a hard, brittle phase formed by rapid cooling), and austenite (a face-centered cubic phase that can be transformed into other structures).

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