Answer:
Creep
Step-by-step explanation:
Creep is a type of deformation that occurs when continuous and long term mechanical stresses are being subjected to a material. Material deformation is observed even if the stresses are below the yield strength of the material, . The effect of creep is more pronounced if there is an application of heat.
In a study of turbine blades it has been shown that at the location where creep is present there was micro-structural degradation. In other places there was no micro-structural degradation.