The steel surfaces can be hardened by carburization. The carbon environment is used to set the surface carbon concentration at 1.0 wt %. The initial carbon content of the steel (C0) is 0.2 wt %. Using the error function table, calculate how long it will take at 1000 deg C to reach a carbon content of 0.6 wt % [i.e. C-Co/Cs-Co=0.5] at a distance 1 mm from the surface.

source: f ncuns, vi. nvianuwis anu 1. A. stegun, Eds., National Bureau of Standards. Applied Mathematics Series 55, Washington, DC, 1972. aee Equation 5.13. Source: Data from L. H. Van Vlack, Elements of Materials Science and Engineering, 4th ed., Addison-Wesley Publishing Co., Inc., Reading, MA, 1980