Technical Paper
The Effect of Microstructure on Edge Ductility of Hot-Rolled Multi- and Single-Phase AHSS Grades
2024-04-09
2024-01-2242
Hot-rolled AHSS grades are utilized in automotive parts where high formability is required. However, these grades can fail below their predicted formability limit due to edge cracking. Microstructure and sheared-edge face quality contribute to the initiation of micro-cracks that lead to edge cracking. While it is established that strain incompatibilities between phases and micro-constituents with differing hardness promote edge cracking, microstructural properties governing edge ductility are not fully understood. The edge ductility of eight hot-rolled automotive AHSS grades with tensile strengths of 600 and 800 MPa, achieved with single- or multi-phase microstructures, are being investigated. The experimental and structural single-phase grades include microstructures comprised of ferritic matrices with composite micro-alloyed nano-precipitates and cementite micro-constituents.