Figure 5

STEM-EDX elemental maps of the STEM needle displaying the intensity of X-ray counts associated with the (a) Fe Kα, (b) Cr Kα, (c) Ni Kα, (d) Mo Lα, (e) Nb Kα, (f) Mn Kα, (g) C Kα and (h) Si Kα peaks. The austenite phase at top and bottom is associated with Fe, Ni and to a lesser extent Mo and Mn, the ferrite phase is predominantly Fe with a small amount of Ni and Cr, the carbides contain Cr, Fe, Mo, C, Ni and Mn, the G-phase precipitate contains Nb, Ni, Mo and Si. The surface of the needle has high carbon and silicon intensities that are associated with organic contamination, primarily due to long exposure under the electron beam.