The fracture properties of a high-strength steel with a body-centered cubic (bcc) crystal structure have been characterized at –196°C by performing tensile tests with different specimen geometries, three-point bending tests using Charpy specimens, and fracture mechanics tests, covering a broad range of stress states under quasi-static conditions. Both strength and ductility of the bcc steel are significantly

Size effects (SEs) impede the mass production of high-performance miniaturised components via micro-forming. Although many studies have examined SEs from multiple aspects, such as flow stress, deformation, and ductile fracture, the SE transitions characterised by the significant changes of these phenomena across the micro- and macroscale remain ambiguous. These SE transitions must be fully and deeply