A plate of iron is exposed to a carbon-rich (carburizing) atmosphere on one side and a carbon-deficient atmosphere on the other side at 1200K. If a condition of steady state is achieved, calculate the diffusion flux of carbon through the plate if the concentrations of carbon at positions of 5 and 10 mm beneath the carburizing surface are 1.2 and 0.8 kg/m3, respectively. Assume the diffusion coefficient is 3×10-10 m2/s at this temperature.

Explanation:

The given data is as follows.

Concentration difference = (1.2 - 0.8)

                                          = 0.4

Diffusion coefficient (D) =

Path length =

Relation between flux and concentration difference is as follows.

Putting the given values into the above formula as follows.

                =

               =

               =

Thus, we can conclude that the diffusion flux of carbon through the given plate is .

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explanation: