A micro-level strain analysis of a high-strength dual-phase steel

Abstract The deformation behaviour of a dual-phase steel with a tensile strength of about 1 000 MPa is investigated at the micro level. In-plane strains are determined by means of in-situ tensile tests in the scanning electron microscope and automatic local deformation analysis (based on digital image correlation). Maps of strain at high and low magnification reveal the network-like formation of deformation bands. In detailed high resolution analyses the sites of highest strain (“hot spots”) are identified. Observations in metallographic cross-sections indicate that these hot spots are frequently the origin of damage initiation.