Striations and Fatigue Crack Growth

10 Fracture Mechanics Approach to Fatigue Crack Propagation 

This dependency on the square of is in accordance with all theoretical models of striation formation [16, 34, 35]. However, the exponent n of the Paris-Erdogan Eq. (10.10) varies from 2 to even 5, as in cast iron. Values of n higher 

Finally, below 30 MPa m (Region I), striations are no longer visible, but a highly faceted fracture surface appears due to crystallographic fracture along intense slip bands. Precisely the same general appearance can be seen on stainless steel type 305 as shown in Fig. 10.23 [36]. 

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