| The growth characterisitics of complex carbides precipitated in Fe-5. 6Cr-C steel and Fe-8. 9Cr-C steel during spheroidizing treatment have been investigated. In order to examine changes in the the crystal structure and composition of complex carbides, they were electrolytically extracted from spheroidized steels. The coarsening of complex carbides has been found to take place by the concentration of chromium in the carbides which have been determined to be (Fe, Cr)_7C₃. The activation energies for the coarsening of complex carbides have been calculated to be 45.9Kcal/mole and 55.7Kcal/mole, respectively. In case of Fe-5. 6Cr-C steel, when spheroidizing for 400 hours at 700℃ the compositional change of the complex carbide has reached to an equilibrium state and consquently the chemical formula for this carbide at that stage has been analysed to be(Fe,_(1.5)Cr_(5.5))C₃. |
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