PSI - Issue 68

Julie Papin et al. / Procedia Structural Integrity 68 (2025) 727–733

730 4

Julie Papin et al. / Structural Integrity Procedia 00 (2025) 000–000

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Fig. 1. (a) Initiation site at a Ti(C,N) inclusion coupled with MnS inclusions; (b) Initiation site at a carbide; (c) EDX spectra showing a Ti(C,N) associated with MnS at initiation site (a); (d) EDX spectra showing a carbide at initiation site (b).

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Fig. 2. Global distribution of initiation types. “Not defined” means that the initiation site was hidden on both specimen halves.

The global distribution of brittle fracture initiator types (i.e., by merging the results from the eight heat treatments) is shown in Fig. 2. Initiation from carbides was predominant. Considering that carbide initiators were systematically located at cleavage plane boundaries, the results plotted in Fig. 2 show the significance of grain boundaries in cleavage initiation; it accounts for three quarters of all observations.