Determine the carburizing time necessary to achieve a carbon concentration of 0.20 wt% at a position 4mm into an iron-carbon alloy that initially contains 0.05 wt% C. The surface concentration is to be maintained at 0.90 wt% C, and the treatment is to be conducted at 1000 C. The diffusion pre-exponential for the material D0 is 5.0x10-5 m2/s and the diffusion activation energy Qd is 284,000 J/mol

Different types of steels contain different elements that alter the characteristics of the steel. for each of the following elements, explain what the element does when alloyed with steel.

Items are similar to the free issue items, but their access is limited. (clo5) a)-bin stock items free issue b)-bin stock controlled issue c)-critical or insurance spares d)-rebuildable spares e)-consumables

Amixture of slurry and mud is to be pumped through a horizontal pipe of diameter 500 mm. the fluid behaves as a bingham plastic with a yield stress of 30 pa and viscosity 0.04 pa.s. describe the effects of the shear stress through a transverse section of the pipe by plotting the variation in shear stress and velocity profile: (i) just before the slurry starts to move (ii) as the slurry flows when the pressure gradient is double that in part (i)