Anisotropic Fracture Behaviour of Progressively Drawn Pearlitic Steel
This paper analyses the differences in fracture behaviour of two cold drawn pearlitic steels with different degree of strain hardening: a slightly drawn bar and a heavily drawn wire. The load-displacement curve F-u was analysed in the two cases, with special emphasis in the characteristic points of the plot: the load defining the end of linear behaviour (Fe), the final fracture load (Fmax) and, in the heavily drawn steel, the pop-in load (FY). Results demonstrate that slightly drawn steels exhibit isotropic fracture behaviour with crack propagation along its own plane (mode I propagation). On the other hand, heavily drawn steels exhibit a markedly anisotropic fracture behaviour with crack deflection (mixed mode propagation), and vertical fracture embryos suddenly appear associated with the pop-in instant. This special fracture mode is a consequence of the markedly oriented microstructure of the heavily drawn steel.
A. Saimoto and M.H. Aliabadi
J. Toribio et al., "Anisotropic Fracture Behaviour of Progressively Drawn Pearlitic Steel", Key Engineering Materials, Vols. 452-453, pp. 1-4, 2011