At what temperature (in Kelvin) will the diffusion coefficient for the diffusion of species A in metal B have a value of 5.20 × 10°10 m2/s, assuming values of 1.3 x 105 m²/s and 224,000 J/mol for Do and Qd, respectively?

Which of the following is independent of flow velocity? a. Transverse diffusion b. Longitudinal diffusion c. Eddy diffusion d. Mass transfer

At approximately what temperature (in Kelvin) would a specimen of an alloy have to be carburized for 2.0 h to produce the same diffusion result as at 760°C for 13 h? Assume that values for Do and Qd are 1.3 × 10-4 m²/s and 135 kJ/mol, respectively. T= i K

You wish to carburize 0.2 wt% C steel ball bearings. The balls have a diameter of 2.5 mm. You anneal them at 930 °C in an atmosphere which fixes the surface carbon concentration at 1 wt% C. (a) How long will it take to raise the average C concentration to 0.6 wt% ? (b) What is the concentration at the centre of each ball at this time?