Chromium carbides phase diagram

The chromium-carbon phase diagram shows the existence of three carbide phases Ct2T,C(, CryC3 and Cr3C2. Only Cr3C2 has industrial importance and it is manufactured by the carburization of chromium(IIl) oxide under a hydrogen atmosphere. 

Kuol] Kuo, K., Carbides in Chromium, Molybdenum, and Tungsten Steels , J. Iron Steel Inst., 173, 363-375 (1953) (Crys. Structure, Phase Diagram, Phase Relations, Experimental, 45)... 

One of the most important attributes of nickel with respect to the formation of corrosion-resistant alloys is its metallurgical compatibility with a number of other metals, such as copper, chromium, molybdenum, and iron. A survey of the binary phase diagrams for nickel and these other elements shows considerable solid solubility, and thus one can make alloys with a wide variety of composition. Nickel alloys are, in general, all austenitic alloys however, they can be subject to precipitation of intermetallic and carbide phases when aged. In some alloys designed for high-temperature service, intermetallic and carbide precipitation reactions are encouraged to improve properties. However, for corrosion applications, the precipitation of second phases usually promotes corrosion attack. The problem is rarely encountered because the alloys are supplied in the annealed condition and the service temperatures rarely approach the level required for sensitization. 

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