Assessment and Quantification of Damage in the Grade 91 Steel PTZ_Final Submitted_.pdf (1.14 MB)
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Assessment and quantification of damage in the grade 91 steel partially transformed zone

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conference contribution
posted on 08.06.2020, 14:08 authored by John Siefert, Jonathan Parker, Ryan Maclachlan, xin xie yang, Rachel ThomsonRachel Thomson
Damage in the grade 91 steel partially transformed zone has historically been associated with many different types of features in the microstructure. Susceptible features responsible for the nucleation of damage are frequently cited to include particles such as laves phase, coarse M23C6, inclusions, nitrides, or interactions between creep strong and creep week grains, grain boundaries and potentially other sources. Few studies have attempted to link these observations on a statistically relevant basis using 2D or 3D microscopy techniques. In this study, 2D assessment using scanning electron microscopy (SEM) and quantification techniques such as energy dispersive x-ray spectroscopy (EDS) and electron backscatter diffraction (EBSD) are utilized in combination with 3D serial sectioning of large volumes using plasma focused ion beam milling (P-FIB) and simultaneous EDS to evaluate an interrupted cross-weld creep test. The cross-weld creep test was performed using a feature-type geometry, in parent material susceptible to the evolution of creep damage and interrupted at an estimated life fraction of 70%. The findings from these evaluations provide perspective on the features in the microstructure responsible for the nucleation and subsequent growth of the observed damage.



  • Aeronautical, Automotive, Chemical and Materials Engineering


  • Materials

Published in

Joint EPRI-123HiMAT International Conference on Advances in High-Temperature Materials (2019)


22 - 34 (13)


Joint EPRI-123HiMAT International Conference on Advances in High Temperature Materials


ASM International


AM (Accepted Manuscript)

Publisher statement

This paper is made available as an electronic reprint with the permission of ASM International for the Loughborough Institutional Repository. Reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this article for a fee or for commercial purposes, or modification of the content of this article is prohibited.

Acceptance date


Publication date







John Shingledecker; Takuyama Masao


Nagasaki, Japan

Event dates

21st October 2019 - 25th October 2019


Prof Rachel Thomson. Deposit date: 7 June 2020

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