Fick second law of diffusion in solids.Subject a piece of steel to a case hardening process in which carbon is forced by diffusion through a layer on the surface of the piece. For this purpose, the piece of steel will be placed in a carbon-rich atmosphere in a special furnace. The temperature of the piece will be maintained at 650C. Determine the time that it will take to reach a concentration of 0.3% by weight carbon at a distance of 4mm from the surface of the piece, which was originally made of 1010 steel. I am confussed on this qiestion. I found thisproblem in Callisters, An Introduction to Materials Science and Engineering book.