|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Atom Probe Tomography for Advanced Characterization of Metals, Minerals and Materials
||Investigation of Carbon Redistribution in Martensite during Room Temperature Aging by Correlative TEM and APT
||Wenjun Lu, Michael Herbig, Christian Liebscher, Lutz Morsdorf, Ross Marceau, Gerhard Dehm, Dierk Raabe
|On-Site Speaker (Planned)
For many years, the formation of the transition carbides with carbon (C) contents between 25 and 33.3 at. % in martensite has been controversially discussed. Their rapid formation during cooling makes it difficult to draw clear conclusions about their chemistry and crystallography. Here we investigate the structure and chemistry of carbides that formed in Fe-15Ni-1C (wt.%) martensite after long term aging at room temperature under well-defined experimental conditions. By quenching this alloy in liquid nitrogen, carbon-oversaturated martensite with immobile carbon was formed. The temperature was increased back to room temperature where C had high enough mobility and the alloy was aged for two to three years to investigate the structural and chemical changes that occurred during room temperature aging. A detailed TEM and APT analysis of material in the 2 years aged condition revealed the formation of plate-like, nanoscale precipitates (~1 nm) within the martensitic phase, identified as orthorhombic η-Fe2C.
||Planned: Supplemental Proceedings volume