Analysis of Crack Morphologies and Patterns from Thermal Fatigue using X-ray Tomography

The paper describes different assessment techniques such as X-ray computed tomography and time-of-flight diffraction (TOFD) for mapping of complex but representative thermal fatigue damage in 316L steel pipes. The observed damage patterns are very complex with interacting circumferential and axial cracks. It was confirmed by detailed microscopic post-test analyses that TOFD measures the crack depth reasonably well but only X-ray tomography reveals the full three-dimensional character of the fatigue damage. The fatigue life of the component was also modelled by a Paris' crack propagation and non-linear kinematic cyclic plasticity model with a single crack. The crack depth vs. number of cycles was captured surprisingly well indicating that crack interaction did not play a major role for the assessment of the fatigue life.

NILSSON Karl-Fredrik;  RIPPLINGER Stefan;  BRUCHHAUSEN Matthias;  RUIZ MORENO Ana Maria;  FISCHER Burkhard;  GUPTA Mohita; 

2015-01-05

ELSEVIER BV

JRC90297

1877-7058,   

https://publications.jrc.ec.europa.eu/repository/handle/JRC90297,   

10.1016/j.mspro.2014.06.353,