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

Answer:

The right answer is "16.5 hrs".

Explanation:

Given values are:

$x_1=2.6 \ mm$

$t_1=3 \ hrs$

$x_2=6.1 \ mm$

As we know,

⇒ $\frac{x^2}{Dt}=constant$

or,

⇒ $\frac{x_1^2}{t_1} =\frac{x_2^2}{t_2}$

⇒ $t_2=(\frac{x_2}{x_1})^2\times t_1$

By putting the values, we get

       $=(\frac{6.1}{2.6} )^2\times 3$

       $=5.5\times 3$

       $=16.5 \ hrs$