Carbon is diffused on the surface of a steel plate by carburization heat treatment. Steel contains 0.20% carbon. The carburization process is applied at 1000 ° C in methane gas (CH4) atmosphere and...

Carbon is diffused on the surface of a steel plate by carburization heat treatment. Steel contains 0.20% carbon. The carburization process is applied at 1000 ° C in methane gas (CH4) atmosphere and the amount of carbon in the furnace environment is 1.3%. Find the diffusion time required for the area from the surface of the steel to a depth of 0.6 mm to reach 0.9% carbon. The diffusion coefficient at 1000 ° C is 3x10-11 m2 / sec.