Investigation of the Tensile Deformation and Fracture of a Dual-Phase Steel

摘要

An analysis of the tensile deformation and fracture of a commercial dual-phase steel was conducted with emphasis on the roles that the individual phases have in these processes. It was observed that the deformation of ferrite is somewhat inhomogeneous, as suggested by the nonuniform appearance of slip lines in ferrite grains. The plastic deformation of martensite, as determined by changes in the particles' average aspect ratio, was found to be appreciable only at strains much higher than the uniform strain to necking. The mechanism of failure was one of void formation, growth and coalescence. Void formation was observed to most frequently occur between the poles of two closely-spaced martensite particles situated on ferrite grain boundaries.