PSI - Issue 42

Jean-Baptiste Delattre et al. / Procedia Structural Integrity 42 (2022) 886–894 Jean-Baptiste Delattre / Structural Integrity Procedia 00 (2019) 000–000

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Fig. 4. Distribution of the fracture initiation sites along the ductile-to-brittle transition for each cooling rate. The experimental points have a small o ff set along the horizontal axis for readability reasons, testing temperatures being respectively -125°C, -100°C, -75°C, -50°C, and -25°C.

Fig. 5. Examples of the di ff erent types of fracture initiation sites that were observed in impact toughness specimens. The left and right pictures depict the same site at di ff erent magnifications.

Estimates of this critical cleavage fracture stress were tentatively derived from the instrumented Charpy curves with the so-called “load diagram” method (Chaouadi and Fabry) 7. This method allows comparisons between the microstructures in the same strain state, namely, at the onset of general yielding of the Charpy specimen. For each