A carburizing gas at 1000 C maintains a 1.0% carbon concentr

A carburizing gas at 1000 C maintains a 1.0% carbon concentr.
A carburizing gas at 1000 C maintains a 1.0% carbon concentration at the surface of a steel part whose initial carbon content is 0.2%. How long would it take to reach a carbon content of 0.5% at a depth of (a) 1.2 mm from the surface, and (b) 2.5 mm from the surface? The diffusion coefficient of carbon in steel is 3.5 x 10-11 m2/s. Q. 3. A porous solid was brought in contact with a liquid coating. The liquid was wicked in the pores. Using the property data give below, calculate the rate of penetration at the end of 2 min. from the start assuming pores to be straight capillaries of 10 micrometer diameter. Surface tension ( lv) of liquid: 0.80 N/m, contact angle: 22 , and viscosity: 0.0035 Pa.s. Will penetration rate increase or decrease with increasing time? Q. 4 Calculate the energy in Joules required to evaporate liquid gold at its boiling point (2857 C) to form a 5 micrometer thick coating on all surfaces of a solid cylindrical disc of 4 cm diameter and 2 cm thickness. The vapor pressure temperature relationship for liquid gold is: The atomic weight of gold is 196.9, and the density of gold is 19.3 g/cc.
A carburizing gas at 1000 C maintains a 1.0% carbon concentr