PSI - Issue 28

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Jesús Toribio et al. / Procedia Structural Integrity 28 (2020) 2404–2409 Jesús Toribio / Procedia Structural Integrity 00 (2020) 000–000

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Fig. 8 sketches the micromechanics of LAD in the case of heavily cold drawn pearlitic steel. The crack changes its propagation direction after a certain subcritical crack growth by LAD in mode I because of the presence in the heavily drawn material of pearlitic pseudocolonies extremely slender, with anomalous (too large) local interlamellar spacing and even with pre-damage that makes them preferential fracture paths with minimum local resistance.

Fig. 8. Micromechanism of LAD by anodic dissolution of the fibers or plates (mode I crack growth) and posterior mechanical fracture of a slender pearlitic pseudocolony.. 4. Curling of pearlitic lamellae in cold drawn pearlitic steel: Resembling van Gogh and Bernini Curling of pearlitic lamellae (see this phenomenon in the longitudinal section of Fig. 2) in heavily cold drawn pearlitic steels produces a curved structure that, from the geometrical perspective, can be analysed in two dimensional (2D) section and, in general terms, according to the full three-dimensional (3D) viewpoint. In a 2D geometrical analysis, such a curved arrangement resembles the appearance of the sky in the painting of Vincent van Gogh so that it could be called van Gogh sky (VGS) or, more properly, van Gogh texture (VGT), and it is represented by the van Gogh painting of Fig. 9. In a 3D geometrical analysis, curling of pearlite (ferrite/cementite) resembles the texture of Bernini sculpture, so that it could be called Bernini sculpture texture (BST), and a superb example is the Ecstasy of Saint Teresa in Cornaro chapel in Santa Maria della Vittoria church in Rome (Fig. 9).

Fig. 9. Noon rest by Vincent van Gogh and Ecstasy of Saint Teresa by Gian Lorenzo Bernini .

5. Crack deflection in cold drawn pearlitic steel: Resembling Mantegna and Picasso Crack deflection in heavily cold drawn pearlitic steel (Figs. 3-8) resembles the change of angle in the painting Dead Christ by Andrea Mantegna (Fig. 10), so that the term Mantegna’s Dead Christ Perspective (MDCP) could be coined. The described painting contains a relevant and innovative change of point of view in the figure of the Dead Christ (rotated 90º from the traditional perspectives in classical painting) with his body axis perpendicular to the canvas ( foreshortening perspective ). The kinked crack path in heavily cold drawn pearlitic steel (Figs. 3-8) can also be associated with the angled line and the change of viewpoint of the cubist painting by Picasso (Fig. 10), so that a new concept could be coined in this regard: the Picasso painting perspective (PPP).