PSI - Issue 59

Jesús Toribio et al. / Procedia Structural Integrity 59 (2024) 98–103 Jesús Toribio / Procedi a Structural Integrity 00 (2024) 000 – 000

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Fig. 4. Micromechanical model of HAMD (TTS) in pearlitic steels with lamellar microstructure: (a ) trans-lamellar cracking path (TLCP) consisting of either PT or SCP, i.e., a sort of HELP manifested in the form of TTS and resembling MSST; (b) inter-lamelar cracking path (ILCP) consisting of PD. i.e., a sort of HEDE manifested in the form of EOTTS and resembling DWST. 5. Conclusions At the micro- or nano-levels, the formation of HAMD by TTS could represent a combination of HELP and HEDE manifested as pearlite tearing (PT), i.e., a sort of HELP or, alternatively, as pearlite delamination (PD). i.e., a sort of HEDE. With regard to the local phenomenon of HELP by PT to create TTS, the Miller-Smith mechanism of shear cracking of pearlite (SCP) could be the responsible, in the form of fracture of the more brittle cementite lamellae by local shear cracking of the more ductile ferrite bands. The locally-ductile micro-mechanism of PT or SCP (a sort of HELP) generates a trans-lamellar cracking path (TLCP) whereas, on the other hand, the locally-brittle micro-mechanism of PD (a sort of HEDE) generates in turn an inter-lamellar cracking path (ILCP). While the TLCP (consisting of either PT or SCP, i.e., a sort of HELP) is manifested in the form of TTS and resembles MSST, the ILCP (consisting of PD. i.e., a sort of HEDE) is manifested in the form of EOTTS and resembles DWST. Acknowledgements The author wishes to kindly and sincerely acknowledge the continuous and long-standing financial support to his scientific research in the field of fracture & structural integrity provided by the following Spanish Institutions: Ministry for Science and Technology (MICYT; Grant MAT2002-01831), Ministry for Education and Science (MEC; Grant BIA2005-08965), Ministry for Science and Innovation (MICINN; Grant BIA2008-06810), Ministry for Economy and Competitiveness (MINECO; Grant BIA2011- 27870) and Junta de Castilla y León (JCyL; Grants SA067A05, SA111A07, SA039A08 and SA132G18). In addition, acknowledgement is given to two companies: E MESA T REFILERÍA (La Coruña. Spain) and T REFILERÍAS Q UIJANO (Los Corrales de Buelna, Santander, Spain) for providing the pearlitic steel wires.