The decarburization of a steel can be carried out by placing the steel in a vacuum (i.e., the carbon concentration is zero) at elevated temperature. Just like the carburization, this process follows the Fick's second law of diffusion.
a. Find the expression to describe the concentration profile of carbon Cx as it diffuses out of a long steel bar with initial carbon concentration C0.
b. Compute the concentration of carbon at 0.2 mm from the carbon-free surface of the 1030 steel bar after 1 hour in vacuum at 1000 degrees Celsius. Take the initial carbon concentration of the 1030 steel bar to be 0.3 wt%.
c. If the decarburization of the 1030 steel bar is carried out in vacuum at 800 degrees Celsius, what is concentration of carbon at 0.2 mm from the carbon-free surface of the 1030 steel bar after 1 hour?