English is not my native language. I am referring to fatigue caused by thermal cycling. Annealing for one year is done to test the chemical stability of the all

English is not my native language. I am referring to fatigue caused by thermal cycling. Annealing for one year is done to test the chemical stability of the alloy and ensure that there is no migration or segregation of alloy elements. There may be unstable hydrodynamic phenomena in a pipe or heat exchanger, which generates a large number of thermal cycles. Such as the instability of a vortex in a mixing or heat exchange zone. This is a different ageing mechanism. It is very complicated and time-consuming to test in the laboratory.