Sheet of steel 4.3 mm thick has nitrogen atmospheres on both sides at 1200°c and is permitted to achieve a steady-state diffusion condition. the diffusion coefficient for nitrogen in steel at this temperature is 5.1 × 10-11 m2/s, and the diffusion flux is found to be 4.9 × 10-7 kg/m2-s. also, it is known that the concentration of nitrogen in the steel at the high-pressure surface is 4.2 kg/m3. how far into the sheet from this high-pressure side will the concentration be 2.7 kg/m3? as