Question

A sheet of steel 2.5 mm thick has nitrogen atmospheres on both sides at 900 c and is permitted to achieve a steady-state diffusion condition. The diffusion coefficient for nitrogen in steel at this temperature is 1.2 x 10-10 m2 /s, and the diffusion flux is found to be 1.0 x 10-7 kg/m2 -s. Also, it is known that the concentration of nitrogen in the steel at the high-pressure surface is 2 kg/m3 . How far into the sheet from this high pressure side will the concentration be 0.5 kg/m3 ? Assume a linear concentration profile.

Answer 1

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