Abstract
The microstructure evolution and mechanical properties of a Fe-32Cr-4Ni-4Cu model alloy after long-term thermal aging at 475 °C was investigated in this study. The spinodal decomposition of the model alloy during thermal aging and the crystal structure evolution of Cu-rich precipitates were observed and analyzed using high-resolution transmission electron microscopy (TEM). It was revealed that after long-term thermal aging, the crystal structure of the precipitated Cu-rich phases in the Fe-32Cr-4Ni-4Cu model alloy transformed from a BCC structure to a multi-twin 9R or 2H structure, ultimately transforming into a stable FCC structure. During long-term thermal aging at 475 °C, the precipitated Cu-rich phase and the Cr-rich ’-phase produced by spinodal decomposition cause an increase in the hardness of the model alloy. The hardness of the model alloy in the early stage of thermal aging greatly depends on the Cu-rich precipitates. After continuous thermal aging for 1000 h, the hardness of the alloy depends on the Cr-rich ’-phase. The results of an oscillographic impact test indicate that the fracture mechanism of the model alloy after thermal aging at 475 °C is brittle fracture, which is mainly influenced by the precipitation of Cu-rich phases during the thermal aging process.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: 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.
