Annealing can repair a material by allowing atoms to find the minimum energy state; since solids have a surface tension this process will allow cracks to fuse and reverse fatigue. However, annealing comes with it's evil twin: creep. If the atoms have enough thermal energy to remove defects form the crystal they likely will also slowly move in the direction of applied force; the material behaves like a very viscous liquid.
But is it possible, given the right material and temperature, to have annealing without creep? If the energy barrier to remove a dislocation is less than the energy barrier to pull an atom out of the crystal lattice, there could be a temperature sweet-spot in which materials wouldn't fatigue but wouldn't creep either?