Abstract
ABSTRACT Six {Ni,Co}-based alloys containing 25wt-%Cr, 0.4wt-%C and 1.6wt-%Ti were cast and subjected to metallographic characterisation before and after exposure for 70 h in air at 1250°C, the highest temperature at which these alloys may be used under low applied stresses. The alloys based mainly on nickel contain principally chromium carbides while TiC is the principal carbide phase in the alloys mainly based on cobalt. The oxidation resistance is the best for the alloys richer in nickel than in cobalt, but titanium has the same effect for all alloys, whatever the base element: after oxidation it is present as an external TiO2 layer covering chromia. The presence of this outermost more (Ni-based alloys) or less thick (Co-based alloys) TiO2 scale on the outer face of the external chromia scale, is expected to have a protective role against chromia volatilisation, phenomenon which can be very important at so high temperature.
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.
