Beam-broadening effects in STEM/EDS measurement of radiation-induced segregation in high-purity 304L stainless steel

Technical Report · Wed Oct 01 04:00:00 EDT 1997

DOI:https://doi.org/10.2172/554847· OSTI ID:554847

Busby, J T; Was, G S ^[1]; Allen, T R ^[1]; Kenik, E A ^[2]; Zaluzec, N J ^[3]

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1. Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Nuclear Engineering and Radiological Sciences
2. Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.
3. Argonne National Lab., IL (United States). Metals and Ceramics Div.

Radiation-induced segregation (RIS) is the spatial redistribution of elements at defect sinks such as grain boundaries and free surfaces during irradiation. This phenomenon has been studied in a wide variety of alloys and has been linked to irradiation-assisted stress corrosion cracking (IASCC) of nuclear reactor core components. Therefore, accurate determination of the grain boundary composition is important in understanding its effects on environmental cracking. Radiation-induced segregation profiles are routinely measured by scanning-transmission electron microscopy using energy-dispersive X-ray spectroscopy (STEM-EDS) and Auger electron spectroscopy (AES). Because of the narrow width of the segregation profile (typically less than 10-nm full width at half-maximum), the accuracy of grain boundary concentration measurements using STEM/EDS depends on the characteristics of the analyzing instrument, specifically, the excited volume in which x-rays are generated. This excited volume is determined by both electron beam diameter and the primary electron beam energy. Increasing the primary beam energy in STEM/EDS produces greater measured grain boundary segregation, as the reduced electron beam broadening a smaller excited volume. In this work, the effect of beam broadening is assessed on segregation measurements in a 304L stainless steel sample irradiated with 3.2 MeV protons at 400 C to doses of 3.0 and 0.1 dpa. The STEM/EDS measurements are also compared to measurements made using AES.

• Research Organization: Argonne National Lab., IL (United States); Michigan Univ., Ann Arbor, MI (United States); Oak Ridge National Lab., TN (United States); Oak Ridge Associated Universities, Inc., TN (United States)
• Sponsoring Organization: USDOE Office of Energy Research, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38; FG02-93ER12130; AC05-96OR22464; AC05-76OR00033
• OSTI ID: 554847
• Report Number(s): ANL/MSD/CP--94776; CONF-970834--; ON: DE98050441
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
36 MATERIALS SCIENCE
ELECTRON MICROSCOPY
EXPERIMENTAL DATA
PHYSICAL RADIATION EFFECTS
REACTOR MATERIALS
SEGREGATION
STAINLESS STEEL-304L
X-RAY SPECTROSCOPY