The surface of a steel gear made of 1020 steel (0.20 wt % C) is to be gas-carburized at 927 deg C. Calulate the carbon content at 0.95mm below the surface of the gear after an 8 hour carburazing time. Assume the carbon content at the surface of the gear is 1.25 wt %. D (C in y iron) at 927deg C = 1.28 x 10^-11 m^2/s.