Question

A carburizing process is carried out on a 0.10% C steel by introducing 1.0% C at the surface at 980°C, where the iron is FCC. Calculate the carbon content at 0.01 cm, 0.05 cm, and 0.10 cm beneath the surface after 1 h.

Answer 1

At X= 0.01 :Cx=0.87%C

At X=0.05 :Cx=0.43%

At X=0.10 : Cx= 0.18%C

Step-by-step explanation:

Using constant values from literature

D=0.23exp[-32900/(1.987)(1213)]=42*10-8cm2/s

Also(1-Cx/1-0.1)=erf[x/(2✓(42*10^-8)(3600)]=erf(x/0.778)

At X=0.01:erf(0.01/0.0778)

So erf(0.1281)*0.9=1-Cx Cx=1+erf(0.1281)*0.9=0.87%C

For X=0.05 : erf(0.05/0.0778)*0.9=1-Cx

Cx= 0.43%C

For X=0.10:erf ( 0.10/0.778)*0.9=1-Cx

Cx= 0.18%C