Abstract
In this study, software for 3-dimensional image reconstruction from two stereo images was developed. The software was applied to ductile and brittle fracture surfaces of duplex stainless steel and the validity was evaluated. The procedure for 3-dimensional image reconstruction was as follows; first, digitizing two micrographs of standard and oblique image by an image scanner, second, searching homologue points by using template matching algorithm to calculate the elevation from measured parallax, and finally displaying reconstructed 3-dimensional images on a monitor. Fractographic analysis for ductile and brittle fracture surfaces of ferritic-austenitic duplex stainless steel was performed by means of the developed software. The reconstructed images obviously reveal the elongated dimple rupture which originates from inclusions in ductile fracture and cleavage cracks which are arrested by austenite grains and re-initiate from other regions in brittle fracture. The reconstruction was also applied to a brittle fracture surface of ferritic stainless steel tested at 77K. It can be seen that cleavage steps appearing as river patterns are detectable and reconstructed when their elevation is greater than 2μm at the scanning resolution of 150 dpi and 1μm at the resolution of 300 dpi in this study.
