Abstract
The effects of long-term exposure to high temperature (800 and 900°C for up to 20,000h) on the microstructure evolution of a Ni–Cr–W superalloy (Alloy 230) were investigated. After long-term aging at 800°C, extensive precipitation of the secondary Cr-rich M23C6 carbides was observed. In addition, the internal dissociation of W-rich primary η-M6C carbides was observed, such as, W-rich M6C→α-W, Cr-rich M23C6, and W-depleted Ni-base matrix. After long-term aging at 900°C, precipitation of Cr- and Ni-rich phase and α-W phase was observed in some areas at the expense of the secondary Cr-rich M23C6 carbides. Meanwhile, the dissociation of the primary M6C carbides was less significant at 900°C. Long-term aging at both temperatures resulted in a decrease in tensile elongation while an increase in strength was minimal after aging at 900°C. The degradation of tensile property depended on the evolution of Cr-rich M23C6 carbides, Cr- and Ni-rich precipitates, and α-W phases but not on the primary M6C carbides.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.