Metallographic Preparation of Incoloy 800 Tube Material for EBSD

A.J. Lockley
2015 Microscopy and Microanalysis  
Incoloy 800 is a nickel-iron-chrome alloy used where high temperature-and corrosion -resistance is required with typical configuration and application being tube material for heat-exchangers. During manufacturing, the boilers tubes are subject to cold-work introducing residual strain into critical regions of the tube. In characterizing the impact of this cold-work on the microstructure, tube material was prepared using metallography for examination by Electron Backscatter Diffraction (EBSD).
more » ... challenge associated with sample preparation for this application can be attributed to the the wall thickness of the tube, being only 1 millimeter (Figure 1 ). Sectioning, mounting and polishing of the sample may introduce additional strain, and inflate results obtained by subsequent EBSD. Most such artifacts can be circumvented by electro-polishing, however; this approach brings a different set of complications: electronic differences from inclusions leaving large pits, and heavy rounding of sample edges (an area of specific interest). Standard metallographic mounting methods introduce other complications as well. Modifications to sample preparation, specifically mounting and the final polish, were found to mitigate these complications.
doi:10.1017/s1431927615006637 fatcat:assaezgq6zaflbehgicij3retq