Abstract
The authors have confirmed in the previous paper that vanadium increased the reheat cracking sensitivity of Cr-Mo steels by the role of decreasing the stress relaxation. This role of vanadium may be related to the precipitation hardening induced by vanadium carbide. In this paper, the cracking sensitivity of Cr-Mo-V steels was discussed from the view point of the precipitation of various carbide phases. X-ray analysis was carried out on the carbide phases extracted electrolytically from the simulated-HAZ specimen tempered at 973 K. Following experimental results were obtained on the steels of the chemical composition ranges of 0 to 2%Cr, 0.28 to 0.8%Mo and 0 to 0.4%V. (1) The increase of cracking sensitivity brought by the addition of vanadium corresponds closely to the increse of hardness induced by the secondary-hardening. (2) The steels of lower molybdenum content are originally less sensitive to cracking. With the addition of vanadium, vanadium carbide precipitates and it converts the steels secondary-hardenable, and hence, cracking-sensitive. (3) Steels of higher molybdenum content are originally secondary-hardenable ; this is brought by molybdenum carbide. In the vanadium-bearing steel, vanadium carbide precipitates replacing molybdenum carbide. However, the original cracking sensitivity is varied little by vanadium, because those two carbides induce the secondary hardening of the same magnitude.
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.
