(a) Estimate the activation energy for creep (i.e., Qc in

(a) Estimate the activation energy for creep (i.e., Qc in Equation 8.20) for the S-590 alloy having the steady-state creep behavior shown in figure. Use data taken at a stress level of 300MPa (43,500psi) and temperatures of 650째C and 730째C. Assume that the stress exponent n is independent of temperature.
(b) Estimate eYS at 600째C (873 K) and300MPa.