PSI - Issue 26

Jesús Toribio et al. / Procedia Structural Integrity 26 (2020) 368–375 Toribio / Structural Integrity Procedia 00 (2019) 000 – 000

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7.2. Oriented pearlite with microstructural anisotropy in moderately and heavily cold drawn pearlitic steels: Resembling Donatello Wooden Sculpture Texture (DWST) In oriented pearlitic microstructures the HAMD takes place in the form of EOTTS, as shown in Fig. 8, cf. Fig. 5b, where the fractograph shown in Fig. 8 appears in vertical layout and with the HAMD propagation (crack growth) from the bottom to the top, i.e., with a 90º rotation in relation to the previous fractograph appearing in Fig. 5b. Thu s the microscopic fracture mode by EOTTS showing evidence of HAMD in oriented pearlite develops in a quasi vertical plane (see Fig. 8, left), i.e., along a sort of propagation step deflected (or deviated) almost 90º from the original fatigue propagation direction in mode I (transversely from the wire axis or cold drawing direction). The fractographic mode in Fig. 8 resembles the Donatello Wooden Sculpture Texture (DWST), see Fig. 9.

Fig. 8. Hydrogen-assisted micro-damage (HAMD) in oriented pearlite: enlarged & oriented TTS (EOTTS), cf. Fig. 5b.

Fig. 9. Works by Donatello: Penitent Magdalene and Saint John the Baptist .