An atom probe tomography study of Pb-caustic SCC in alloy 800

作者：Persaud S Y^*; Smith J M^*; Langelier B; Capell B; Wright M D

来源：Corrosion Science, 2018, 140: 159-167.

DOI：10.1016/j.corsci.2018.06.005

• Nickel
• Alloy
• Stress corrosion
• Pb-SCC
• Atom probe tomography

Stress corrosion cracking (SCC) of Alloy 800 was induced in 330 degrees C Pb-caustic solution (pH(330 degrees C) 9.5). These laboratory tests simulated extreme crevice environments in nuclear plants, but do not occur under normal operating conditions. Atom probe tomography (APT) was used to examine crack tips, a powerful but scarcely used technique for this application. APT revealed sub-nanometre scale crack chemistry: successive Ni-rich, de-alloyed regions and segregated Fe- and Cr-rich oxides. Also, APT allowed for quantification of impurities, such as Pb which segregated to oxide-metal interfaces (< 4 at.%). Discussion highlights new mechanistic insights from APT, complementing prior transmission electron microscopy (TEM) analysis.

• 出版日期2018-8-1