Abstract
Abstract The evolution characteristics of the second phases in the weld seams of 2.25Cr-Mo-0.25 V steel in three states – welded, post-weld heat-treated and creep states – during manufacturing and service were evaluated by calculations and observations using optical microscopy, scanning electron microscopy, transmission electron microscopy and X-ray diffraction spectrometry. The results showed that the second phase was M 3C in the as-welded state. The types and quantities of the precipitated phases increased greatly after post-weld heat treatment (PWHT), and M 3C, M 2C, M 7C3, M 23C6 and MX were the main precipitated phases. During PWHT, the amount of M 7C3 decreased, the amounts of M 23C6 and MX increased, and the sizes of the second phases increased. The precipitates coarsened after long-term creep, and M 7C3, M 6C, M 23C6, M 2C, and MX were the main precipitate phases in this state. The size of the MX phase remained relatively stable during long-term creep, which contributed greatly to the creep resistance.
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.
