Mechanical Properties And Crash Worthiness Of Ultrafine Grained Multi-Phase Steel Sheets For Automotive Body Applications

Mechanical properties, formability and crash worthiness of a new sheet steel having an ultrafine grained (UFG) multiphase (MP) microstructure are shown. The fabricated UF-GMP steel showed significant work hardening caused by deformation induced martensitic transformation of retained austenite, which resulted in a combination of high strength and large tensile elongation. It was confirmed by dynamic collapse test and FEM simulation that the large work hardenability of the UFG-MP steel promoted compact mode collapse that improved the absorbed energy.