Question

For a steel alloy it has been determined that a carburizing heat treatment of 3-h duration will raise the carbon concentration to 0.38 wt% at a point 2.6 mm from the surface. Estimate the time (in h) necessary to achieve the same concentration at a 6.1 mm position for an identical steel and at the same carburizing temperature.

Answer 1

The right answer is "16.5 hrs".

Step-by-step explanation:

Given values are:

`x_1=2.6 \ mm`

`t_1=3 \ hrs`

`x_2=6.1 \ mm`

As we know,

⇒
`(x^2)/(Dt)=constant`

or,

⇒
`(x_1^2)/(t_1) =(x_2^2)/(t_2)`

⇒
`t_2=((x_2)/(x_1))^2* t_1`

By putting the values, we get

`=((6.1)/(2.6) )^2* 3`

`=5.5* 3`

`=16.5 \ hrs`