"The Enlightenment" wrote in message
om...


All hypersonic aircraft, like the SR71 irrespective of material don't
have fatique problems becuase the heat effectively heat treates
(aneals) any work hardening metal. Titanium, inconel, austenitic
steels all are the same.



Complete and utter cobblers

The normal stress relief temperature for titanium is around 1000 F
and the annealing temperature is closer to 1300 F

source:
Titanium Metals Corporation
Titanium Design and Fabrication Handbook for Industrial Applications

Keith