Final Version of Mats Charact paper 2020.pdf (1.9 MB)
Download fileInfluence of microstructure on cavitation in the heat affected zone of a Grade 92 steel weld during long-term high temperature creep
journal contribution
posted on 2020-10-19, 13:14 authored by X Xu, JA Siefert, JD Parker, Rachel ThomsonRachel ThomsonThe microstructure in the heat affected zone of the multi-pass welds constructed using the 9% Cr tempered martensitic steels is complex and susceptible to premature creep failure. In the present research, a systematic investigation has been conducted after long-term creep exposure in the heat affected zone of a multi-pass weld on the 9% Cr Grade 92 steel to identify the sub-optimal microstructures with a high susceptibility to creep cavitation. The characterisation techniques employed include hardness mapping and a range of electron-based microscopy methods. The results provide quantitative data for microstructure and creep cavities. In this case, preferential creep cavitation has been confirmed in the regions within the heat affected zone that possesses a microstructure with an inhomogeneous distribution of the M23C6 carbides and a refined martensitic grain structure. Creep cavities have been observed on the secondary phase particles including the Al2O3, the MnS and the BN phases. The observations from the current research confirm that creep cavitation preferentially occurs in the partially-transformed zones that were subjected to thermal cycles associated with peak temperatures between the Ac1 and the Ac3 transus temperatures during weld fabrication.
History
School
- Aeronautical, Automotive, Chemical and Materials Engineering
Department
- Materials
Published in
Materials CharacterizationVolume
170Publisher
Elsevier BVVersion
- AM (Accepted Manuscript)
Rights holder
Elsevier Inc.Publisher statement
This paper was accepted for publication in the journal Materials Characterization and the definitive published version is available at https://doi.org/10.1016/j.matchar.2020.110663.Acceptance date
2020-09-20Publication date
2020-09-24Copyright date
2020ISSN
1044-5803Publisher version
Language
- en