Iron-carbon-nitrogen diagram

Fig. 2. A portion of the iron-carbon-nitrogen diagram at 450°C. according to K. H. Jack, where phases are represented as follows + = a, Q = y, O — , = t, X = x, C = Fe C. Reprinted by permission of The Royal Society (London).

Svy] Svyazhin, A.G., Kindop, V.E., El Gammal, T, Solubility of Nitrogen in Liquid Iron-Carbon Alloys , Mater. Sci. Forum, 318-320, 81-88 (1999) (Experimental, Review, Phase Diagram, 21)... 

In a similar feshion, fi. n-pH diagrams can be constructed for other redox half reactions. Some examples are given in Figure 7.8. These diagrams suggest that in oxic seawater = +0.4 V and pH = 8), the stable form of iron is Fe(OH)3, nitrogen is stable as nitrate, sulfur as sulfete, and carbon as bicarbonate, if each of these species reaches redox equilibrivun. 

Figure 8.13. Equilibrium concentrations of biochemically important redox components as a function of pe at a pH of 7.0 (a) nitrogen (b) nitrogen, with elemental nitrogen N2 ignored (c) iron and manganese (d) sulfur (e) carbon. These equilibrium diagrams have been constructed from equilibrium constants listed in Tables 8.6a and 8.6b for the following concentrations Cr (total carbonate carbon) = 10 M [HjSCaq)) + [HS ] -I- [SOri = 10 M [NOj-] + [NOj"] + [NH ] = 10 M = 0.78 atm and thus [NjCaq)] = 0.5 x 10 M. For the construction of (b) the species NH4 , NOj, and NO are treated as metastable with regard to Nj.

Nau2] Naumann, V.F.K., Langenseheid, G., Contribution to the Investigation into the Iron-Nitrogen-Carbon System , (in German), Arch. Eisenhuttenwes., 36(9), 677-682 (1965) (Experimental, Phase Diagram,, 21)... 

Rag] Raghavan, V., C-Fe-N (Carbon-Iron-Nitrogen) , J Phase Equilib., 14(5), 620-621 (1993) (Phase Diagram, Phase Relations, Review, 13)... 

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