Miller, Michael K.
Research staff, Oak Ridge National Laboratory, Oak Ridge, TN
Burke, Mary Grace
Senior research scientist, Westinghouse R&D Center, Pittsburgh, PA
Pages: 20 Published: Jan 1990
Atom probe field-ion microscopy has been used to characterize the ultrafine microstructure of neutron-irradiated A302B and A212B pressure vessel steels, A533B submerged arc welds, and several model Fe-Cu alloys. The atomic spatial resolution of this technique permits a complete microstructural and chemical description of the ultrafine features that control the mechanical properties to be made. A variety of ultrafine features, including roughly spherical and disc-shaped copper precipitates and clusters, copper atmospheres, copper phosphides, phosphorus clusters, spherical and rod-shaped molybdenum carbides, molybdenum phosphides, disc-shaped molybdenum nitrides, and iron nitride precipitates, were observed in these materials. The presence of these features was found to be material dependent. The atom probe also revealed a complex pattern of segregation and precipitation at grain boundaries and segregation to precipitate-ferrite interfaces.
microstructure, atom probe field-ion microscopy, pressure vessel steel, neutron irradiation, atom probe field-ion microscope (APFIM)
Paper ID: STP49446S