ELyT Global

OPSCC

OPSCC: Optimizing surface finish to Prevent SCC initiation in energy industries

Axes: Energy, Surfaces & Interfaces

Leaders: Hiroshi ABE (TU) & Benoît TER-OVANESSIAN (MATEIS, INSA)

Participants: Takamichi MIYAZAKI (GSE, TU), Nicolas MARY (ELyTMaX, TU), Marion FREGONESE (MATEIS, INSA-Lyon), Yutaka WATANABE (GSE, TU), Bernard NORMAND (MATEIS, INSA-Lyon)

Double degree PhD student: Kathleen JAFFRE

It has been recently recognized that surface finish has strong impact on SCC susceptibility of alloys in various kinds of environments, including boiling water reactor coolant, primary water of pressurized water reactors, and chloride containing water. Industry needs appropriate surface finish procedures to reasonably minimize SCC susceptibility of alloys. To achieve an effective answer to this demand, we need to know the following items as a function of surface treatment:

  • Physical metallurgy of alloy surface (micro- and nano-structure of surface).
  • Electrochemical properties, in particular, stability of passivity.
  • SCC initiation dynamics (embryo formation and repassivation, coalescence of micro-cracks).

All those properties need to be linked to each other to understand the effect of surface finish on SCC susceptibility of alloys.

In 2017-2018, passive film characterizations have been performed at MATEIS on material provided by GSE-TU. The film properties (capacitance, resistance, number of defect) were evaluated for several surface preparation that will be used for SCC experiments in GSE-TU.