Hikari Corporation

Compared to austenite, the gap between ferrite atoms is narrower.

* For details, see the Youtube video ↓

https://www.youtube.com/watch?v=u6Izix4uVZU

 

 

 

Let's calculate the size of the gap between the atoms of ferrite, which is a body-centered cubic lattice.

↓

 

Cut out the body-centered cubic lattice on the orange side.

 

↓

 

* A ... Length of one side of body-centered cubic lattice r ... Atomic radius

 

From the figure

4r = √3a

 

Because the atomic radius of iron is 126pm

√3a = 4 × 126

A = 290.984pm

 

The

The short gap x and the long gap y are ...

x = a-2r

= 38.934pm

 

y = √2a-2r

= 174.409pm

 

Since the atomic radius of carbon is 70pm, it cannot enter the gap of x.

Ferrite cannot dissolve carbon in solid solution because the gaps between atoms are narrow.

I will calculate the gaps between the atoms of austenite, which is a face-centered cubic lattice, in the next article.