| Abstract: | An observation of the deformation and fracture behaviour of low carbonmartensite-ferrite dual-phase steel was performed using SEM with tensile-stage andautograph test machine.It was shown that the microcracks are nucleated at theinterface of martensite/ferrite and along the martensite boundaries of differentorientations,or initiated owing to the fracture of martensite laths under defor-mation of tensile stress.The cracks may propagate by the coalescence of maincrack and the growth of microcracks,then rapidly connect with each other alongthe strong shear deformation zone.Its micro-feature is appeared as the dimplefracture and seems to be of the ductile fracture mechanism. |
