An alloy is evaluated for potential creep deformation in a short-term laboratory experiment. the creep rate is found to be 1% per hour at 800°c and 0.055% per hour at 700°c.
(a) calculate the activation energy for creep in this temperature range.
(b) estimate the creep rate to be expected at the service temperature of 500°c.

a) Q = 251.758 kJ/mol

b) creep rate is    

Explanation:

we know Arrhenius expression is given as

where

Q is activation energy

C is pre- exponential constant

At 700 degree C creep rate is% per hr

At 800 degree C  creep rate is% per hr

activation energy for creep is =

solving for Q we get

Q = 251.758 kJ/mol

b) creep rate at 500 degree C

we know