Microstructures of oxide films formed in alloy 182 BWR core shroud support leg cracks
Paper i proceeding, 2018

This paper contributes to a TEM examination on the oxide films formed at three locations along a crack path in Alloy 182 weld from a BWR core shroud support leg, namely, the crack mouth, the midway between the mouth and the crack tip, and the crack tip. In the crack mouth the oxide film was approximately 1.6 μm in thickness and consisted of relatively pure NiO. The midway oxide film was mainly a nickel chromium oxide with a film thickness of 0.3 μm. At the crack tip the oxide film was a nickel chromium iron oxide with a film thickness of 30 nm. In all studied locations the main oxides had the similar rocksalt structure and the cracks were much wider than the thicknesses of the oxide films. It probably suggests that the corroded metal was largely dissolved into the coolant. The different dissolution rates of nickel, chromium and iron cations in the oxide films are clearly displayed with the compositions of the residual oxides. The oxide stability under different redox potentials along the crack path is briefly discussed.

FIB

Crack

BWR

Oxide microstructure

TEM

SEM

Core shroud

Support leg

Författare

Jiaxin Chen

Studsvik

Daniel Jädernäs

Studsvik

Fredrik Lindberg

Swerea KIMAB

Henrik Pettersson

Chalmers, Fysik, Materialens mikrostruktur

Martin Bjurman

Studsvik

Kwadwo Kese

Studsvik

Anders Jenssen

Studsvik

Massimo Cocco

Forsmarks Kraftgrupp AB

Hanna Johansson

Forsmarks Kraftgrupp AB

Minerals, Metals and Materials Series

2367-1181 (ISSN) 2367-1696 (eISSN)

Vol. Part F11 417-431

18th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors
Portland, USA,

Ämneskategorier

Materialkemi

Annan materialteknik

Korrosionsteknik

DOI

10.1007/978-3-319-68454-3_33