T. E. Capobianco, M. E. Hanson, Lockheed Martin, Schenectady, NY

Summary: Two ductility dip cracks (DDC) embedded in EN52 weld metal were located using x-ray computed tomography. These DDC fracture surfaces were opened for examination in ultra-high vacuum and were never in contact with the atmosphere prior to being examined. Characterization by Auger Electron Spectroscopy showed that the surfaces had a heavy coverage of chromium carbide particles in a titanium enriched region coated with a thin (~10 angstrom) layer of sulfur.