Yunzi Yan’s project description

Project Title

Understanding micro mechanisms in plane strain bending deformation of automotive, ultrahigh-strength Steel alloys.

Project Summary

Roll forming is an incremental bend forming process and is increasingly used in the automotive industry to form Ultra-High Strength Steels (UHSS) with strength levels up to 1800 MPa at room temperature. The process allows for the flexible compensation of shape defects and springback and theoretically significantly higher strength levels could be roll formed. The major limitation of the process is the fracture limit of UHSS in plane strain bending deformation which only allows for the roll forming of a minimum profile radius between 3-4 times the material thickness or higher. Currently, there is only limited understanding of the micro-mechanisms that trigger fracture initiation in bending steel and their dependence on alloy composition and steel processing conditions.

Project Aim

To develop a fundamental understanding of microstructure effects on the material behaviour and forming limits of UHSS in bending-dominated forming.