PSI - Issue 61

Shahriar Afkhami et al. / Procedia Structural Integrity 61 (2024) 53–61 Shahriar Afkhami et al./ Structural Integrity Procedia 00 (2019) 000 – 000

60 8

- The failure of the welded joints was ductile, either on the straight or cold-formed side of the joints, regardless of the degree of cold-forming. The only brittle fracture observed among the specimens was a welded specimen containing porosities, as welding defects, along its fusion line; this case study was identified as an exception and was removed from the comparative evaluations of the research, although its fracture mechanism was identified through fractography to confirm its nature as an exception/error among the trials. Finally, expanding the knowledge on the fracture behavior and mechanisms of cold-formed ultra-high strength

Fig. 5. Fracture surface analysis of the samples with an R of 10 mm on their cold-formed side (DOC ≈ 14%)

steels and completing the current data and design rules that are available in the related codes and standards require more studies similar to the current one, mainly focusing on other types of thermomechanically processed ultra-high strength steels with various degrees of cold-forming. In this regard, the value of microstructural investigations in identifying the reasons behind each fracture mechanism must not be neglected. Hence, it is highly recommended that