A lifting shackle in a glass-making factory is made from a special high-temperature stainless steel. It is expected that the shackle will experience a tensile load of 5kN and the design allows for a maximum creep strain of 1% over the design life of 10,000 operating hours.

The supplier of the alloy has measured the stress exponent, n, to be 4.5, the activation energy, QC , to be 110,000 J/mol and the pre-exponential constant, K₂ , to be 2 ×10^-8(the constants K₂ and n are in MPa, % and hour units).

(a) Calculate the minimum required cross-sectional area of the shackle if operating at 800^oC.

(b) If the temperature were to be increased to 900^oC and the load and cross-sectional area kept the same, what would be the time to 1% strain what would the creep strain be after 10,000 hours?