How long was it in service? is this an infant mortality or long term failure? If the former I'd think bad weld with hydrogen pickup. If it was TMF I'd expect a more flat, featureless surface with oxide consumed morphology. Obviously not HCF, lack of beach marks makes me think no to LCF too...
I was kind of thinking that there may be a calibrated metal strip that has an oxide thickness that correlates to time@temperature. Anyone know of such an animal?
I contacted Tempil directly. Here is their response:
Hello,
Thank you for the inquiry. We do not offer temperature labels with ratings above 554F. The reason is the paper used to produce the labels will not withstand the higher temperatures.
Regards,
Lorraine Keenan
Tempil
Customer Service
The problem is it must last for 3 years and be intact. It will be attached to a gas turbine rotor, under the heat shields. We tried temperature indicating paints (like tempil) and they just oxidize away in that time.
