PSI - Issue 5

George Pantazopoulos et al. / Procedia Structural Integrity 5 (2017) 476–483 G. Pantazopoulos and A. Vazdirvanidis / Structural Integrity Procedia 00 (2017) 000 – 000

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(b) Fig. 7. (a), (b) Optical micrographs, longitudinal section on the bolt showing crack propagation at the thread roots and crests.

4. Conclusions

The findings of failure and fracture analysis conducted for brass machined components, destined to hydraulic installations, can be summarized as follows: a. Hexagonal brass fittings suffered from brittle longitudinal cracking, propagated via an intergranular fashion and followed by ultimate mixed fracture mode (intergranular and shallow-dimpled path). b. Threaded brass components manifested severe thread fracture and detachment together with multiple cracking to the existing – non detached - threads. Evidence of complete intergranular fracture was collected using SEM microfractography. c. A typical microstructure was identified while no relevant microstructural deficiencies were observed in both series of the components, suggesting the presence of sound raw material.