Abstract
The precipitation behavior of γ′ precipitates and mechanical properties of 21Cr-32Fe-41Ni alloy at different aging temperatures were investigated by scanning electron microscopy, transmission electron microscopy, chemical phase analysis, mechanical property tests. The results showed that the precipitates in 21Cr-32Fe-41Ni alloy included γ′ precipitates, MC phases, σ phases after aging heat treatment. There were two precipitation modes of γ′ precipitates: intragranular dispersed precipitation and grain boundary discontinuous precipitation. The number and size of intragranular γ′ precipitates increased with the increase in aging temperature. During the coarsening process, the γ′ precipitates were kept spherical. When the aging temperature was above 740 ℃, the discontinuous precipitation reaction occurred under the combined effect of grain boundary migration and solute diffusion-controlled equilibrium phase growth. According to SEM images, there were four different kinds of morphologies of discontinuous precipitated cellular γ′ at the grain boundaries. They were lamellae precipitates, short rod precipitates, granular precipitates and bidirectional parallel precipitates. When the aging temperature was between 650 ℃ and 740 ℃, the strength of the alloy increased rapidly due to the precipitation of a large number of intragranular spherical γ′, and the precipitation of grain boundary cellular γ′ was one of the main reasons for the toughness of alloy decreased rapidly above 740 ℃.
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.
