Even if a material is under stress that does not semi-permanently deform or break at room temperature (below a certain temperature determined for each material), at high temperatures the material gradually deforms and breaks after a certain period of time. This phenomenon is called creep.
Countermeasures
After a certain period of use, it is necessary to perform the following inspections and evaluations to prevent fracture:
- Subcategory: Creep
- Damage mode: Cracks (Voids)
- Inspection: Microstructure examination and creep test by materials sampled.
- Evaluation: Estimation of remaining life based on material properties, temperature, stress, void propagation and creep test results.
- Actions: Establish criteria (remaining life) for crack removal, repair, component replacement, and material change.