@article{6e7b11813bda486dae51d61376107e28,
title = "Observations of cleavage initiation in ferritic steel",
abstract = "Local Approach (LA) to cleavage fracture models have been under development since the 1980s with the aim of predicting cleavage fracture, including accounting for the effects of temperature, crack-tip geometry and irradiation. This work presents observations of particle behaviour and micro-crack nucleation under stress conditions similar to those ahead of a crack tip, achieved by testing bespoke tensile specimens with a highly constrained volume at temperatures in the material{\textquoteright}s ductile to brittle transition region. This region was examined post-test using a scanning electron microscope to identify and characterise micro cracks and micro-crack initiation defects, such as particles. Supporting finite element analyses were performed to predict the mechanical fields acting on the defects. The results suggested that:• micro-cracks nucleated in the form of damaged, spherical regions around the initiation particle with a cloud of crack tips, rather than as single penny shaped cracks as assumed in LA models; • these damaged regions can be much larger than the initiating particle; • nucleation was more often caused by failure of the particle-matrix interface than particle cracking.",
keywords = "Cleavage fracture, Local approach, Micro-crack",
author = "Michael Ford and Andrey Jivkov and Peter James",
year = "2020",
month = dec,
day = "1",
doi = "10.1016/j.prostr.2020.10.156",
language = "English",
volume = "28",
pages = "1787–1794",
journal = "Procedia Structural Integrity",
issn = "2452-3216",
publisher = "Elsevier BV",
}