Cleavage Fracture Micromechanisms of High Strength Steel and its Heat-Affected Zones

Cleavage Fracture Micromechanisms of High Strength Steel and its Heat-Affected Zones

Morete Barbosa Bertolo, V. (TU Delft Team Vera Popovich)

Popovich, V. (promotor)
Sietsma, J. (copromotor)
Walters, C.L. (copromotor)

Delft University of Technology

2023-03-24

The use of materials in increasingly severe service conditions raises concerns about structural safety with respect to cleavage fracture. There are three main material-related challenges that structures face under harsh environments: 1) the trade-off between strength and toughness; 2) the ductile-to-brittle transition behaviour of BCC high strength steels; 3) the inhomogeneous microstructures found in multiphase steels, thick-section steels, and welded structures. Therefore, the objective of this research is to systematically investigate the cleavage fracture micromechanisms in high strength steels considering diverse microstructures (e.g., as-received commercial steel, thermally simulated heat-affected zones, and grain refined microstructure) and experimental conditions (e.g., plastic constraint and temperature). Thereby, this study provides a thorough understanding of the effect of the microstructural details on cleavage fracture behaviour of high strength steel structures allowing for failure control and improvement of cleavage-resistant steel’s design...

Cleavage fracture toughness
High strength steels
Micromechanisms
Multiphase
Heat-affected zones
Grain refinement
Microstructural characterisation

https://doi.org/10.4233/uuid:ac984b23-c4e1-4bf4-9668-5e3d54aec3ff

978-94-6469-265-5

Institutional Repository

doctoral thesis

© 2023 V. Morete Barbosa Bertolo