Characterisation of handling and service surface damage on Nickel alloys caused by low velocity impacts of blunt hard objects

This paper presents a characterisation of surface damage, more specifically dents, caused by low velocity impacts of blunt objects on RR1000 Nickel superalloys. These are representative of damage that may occur during handling and service of components during manufacturing or maintenance. The characterisation of dents produced in laboratory tests is carried out both in terms of their geometry and the residual stresses the damage. A finite element model is presented and the results are validated in terms of dent geometry produced for different impact velocities. The stress distribution predicted by the numerical model is also compared with experimentally measured stresses via X-ray diffraction for validation of the model. The residual stresses obtained from the finite element (FE) model and their implications to fatigue and crack propagation lives are also discussed here.