View in EDS HTML Full Text PDF Full Text

The Effects of Long-Term High-Temperature Aging on the Microstructural Evolution and Impact Fracture Behavior of Inconel 625 Superalloy.

Saved in:
Bibliographic Details
Title: The Effects of Long-Term High-Temperature Aging on the Microstructural Evolution and Impact Fracture Behavior of Inconel 625 Superalloy.
Authors: Li, Zhining1 (AUTHOR), Li, Kejian1,2 (AUTHOR), Wu, Yao1 (AUTHOR), Cai, Zhipeng1,2 (AUTHOR), Liu, Qu1,2 (AUTHOR) liuqu@mail.tsinghua.edu.cn
Source: Materials (1996-1944). May2026, Vol. 19 Issue 10, p1932. 14p.
Subjects: Inconel, Microstructure, Impact response, Precipitation (Chemistry), Carbides
Abstract: Inconel 625 is widely used in high-temperature structural components because of its excellent strength, toughness, and corrosion resistance. However, long-term exposure to elevated temperatures can induce precipitation of carbides, γ″ phase, and δ phase, leading to microstructural degradation and reduced mechanical reliability. Although precipitation evolution and tensile properties of aged Inconel 625 have been widely studied, the relationship between long-term precipitate evolution and impact fracture behavior remains insufficiently clarified. In this study, solution-treated Inconel 625 alloy was aged at 700 °C and 750 °C for up to 5000 h, with additional stress-assisted aging at 750 °C under 30 MPa and 51 MPa. Impact toughness, microhardness, fracture morphology, and precipitate evolution were systematically investigated. The results show that long-term aging significantly reduces impact toughness at both room and elevated temperatures, with a more pronounced reduction at room temperature. The room-temperature impact energy decreases from 314 J to approximately 10 J and stabilizes after 2000 h. Quantitative analysis shows that γ″ precipitate coarsening follows the Lifshitz–Slyozov–Wagner relationship, indicating diffusion-controlled growth. Stress-assisted aging under the present low stress levels has only a limited influence on precipitate evolution and impact toughness. The toughness degradation is mainly attributed to chain-like grain-boundary carbides and needle-like or plate-like δ phase, which embrittle grain boundaries, segment the austenitic matrix, and limit impact energy absorption. [ABSTRACT FROM AUTHOR]
Copyright of Materials (1996-1944) is the property of MDPI and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
Full text is not displayed to guests.
FullText Links:
  – Type: pdflink
Text:
  Availability: 1
Header DbId: egs
DbLabel: Engineering Source
An: 194116768
AccessLevel: 6
PubType: Academic Journal
PubTypeId: academicJournal
PreciseRelevancyScore: 0
IllustrationInfo
Items – Name: Title
  Label: Title
  Group: Ti
  Data: The Effects of Long-Term High-Temperature Aging on the Microstructural Evolution and Impact Fracture Behavior of Inconel 625 Superalloy.
– Name: Author
  Label: Authors
  Group: Au
  Data: <searchLink fieldCode="AR" term="%22Li%2C+Zhining%22">Li, Zhining</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Li%2C+Kejian%22">Li, Kejian</searchLink><relatesTo>1,2</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Wu%2C+Yao%22">Wu, Yao</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Cai%2C+Zhipeng%22">Cai, Zhipeng</searchLink><relatesTo>1,2</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Liu%2C+Qu%22">Liu, Qu</searchLink><relatesTo>1,2</relatesTo> (AUTHOR)<i> liuqu@mail.tsinghua.edu.cn</i>
– Name: TitleSource
  Label: Source
  Group: Src
  Data: <searchLink fieldCode="JN" term="%22Materials+%281996-1944%29%22">Materials (1996-1944)</searchLink>. May2026, Vol. 19 Issue 10, p1932. 14p.
– Name: Subject
  Label: Subjects
  Group: Su
  Data: <searchLink fieldCode="DE" term="%22Inconel%22">Inconel</searchLink><br /><searchLink fieldCode="DE" term="%22Microstructure%22">Microstructure</searchLink><br /><searchLink fieldCode="DE" term="%22Impact+response%22">Impact response</searchLink><br /><searchLink fieldCode="DE" term="%22Precipitation+%28Chemistry%29%22">Precipitation (Chemistry)</searchLink><br /><searchLink fieldCode="DE" term="%22Carbides%22">Carbides</searchLink>
– Name: Abstract
  Label: Abstract
  Group: Ab
  Data: Inconel 625 is widely used in high-temperature structural components because of its excellent strength, toughness, and corrosion resistance. However, long-term exposure to elevated temperatures can induce precipitation of carbides, γ″ phase, and δ phase, leading to microstructural degradation and reduced mechanical reliability. Although precipitation evolution and tensile properties of aged Inconel 625 have been widely studied, the relationship between long-term precipitate evolution and impact fracture behavior remains insufficiently clarified. In this study, solution-treated Inconel 625 alloy was aged at 700 °C and 750 °C for up to 5000 h, with additional stress-assisted aging at 750 °C under 30 MPa and 51 MPa. Impact toughness, microhardness, fracture morphology, and precipitate evolution were systematically investigated. The results show that long-term aging significantly reduces impact toughness at both room and elevated temperatures, with a more pronounced reduction at room temperature. The room-temperature impact energy decreases from 314 J to approximately 10 J and stabilizes after 2000 h. Quantitative analysis shows that γ″ precipitate coarsening follows the Lifshitz–Slyozov–Wagner relationship, indicating diffusion-controlled growth. Stress-assisted aging under the present low stress levels has only a limited influence on precipitate evolution and impact toughness. The toughness degradation is mainly attributed to chain-like grain-boundary carbides and needle-like or plate-like δ phase, which embrittle grain boundaries, segment the austenitic matrix, and limit impact energy absorption. [ABSTRACT FROM AUTHOR]
– Name: AbstractSuppliedCopyright
  Label:
  Group: Ab
  Data: <i>Copyright of Materials (1996-1944) is the property of MDPI and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.)
PLink https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=egs&AN=194116768
RecordInfo BibRecord:
  BibEntity:
    Identifiers:
      – Type: doi
        Value: 10.3390/ma19101932
    Languages:
      – Code: eng
        Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 14
        StartPage: 1932
    Subjects:
      – SubjectFull: Inconel
        Type: general
      – SubjectFull: Microstructure
        Type: general
      – SubjectFull: Impact response
        Type: general
      – SubjectFull: Precipitation (Chemistry)
        Type: general
      – SubjectFull: Carbides
        Type: general
    Titles:
      – TitleFull: The Effects of Long-Term High-Temperature Aging on the Microstructural Evolution and Impact Fracture Behavior of Inconel 625 Superalloy.
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Li, Zhining
      – PersonEntity:
          Name:
            NameFull: Li, Kejian
      – PersonEntity:
          Name:
            NameFull: Wu, Yao
      – PersonEntity:
          Name:
            NameFull: Cai, Zhipeng
      – PersonEntity:
          Name:
            NameFull: Liu, Qu
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 15
              M: 05
              Text: May2026
              Type: published
              Y: 2026
          Identifiers:
            – Type: issn-print
              Value: 19961944
          Numbering:
            – Type: volume
              Value: 19
            – Type: issue
              Value: 10
          Titles:
            – TitleFull: Materials (1996-1944)
              Type: main
ResultId 1