# C–Fe system > C–Fe system: 12 accepted literature values (invariant reaction 6, phase transition 6) and 0 calculated phase diagram(s) from ORCHID, each value with evidence class, source, page and quote. HTML: https://data.orchid-project.org/systems/C-FE.html · Markdown: https://data.orchid-project.org/systems/C-FE.md 12 accepted literature values from 2 paper(s) (experimental 3, model 3, unspecified 6); 0 calculated phase diagram(s). 17 further extracted value(s) not accepted by the reader-agreement checks are only in the JSON/CSV. Data: [JSON](https://data.orchid-project.org/literature/systems/C-FE.json) · [CSV](https://data.orchid-project.org/systems/C-FE.csv) · [interactive explorer](https://orchid-project.org/data-explorer/#C-FE) · [phases (12)](https://data.orchid-project.org/phases/pages/C-FE.html) · [papers (bibliography)](https://data.orchid-project.org/bibliography/pages/systems/C-FE.html) · [Markdown](https://data.orchid-project.org/systems/C-FE.md) Table: Accepted values by evidence class | Evidence class | Values | |---|---:| | experimental | 3 | | model | 3 | | unspecified | 6 | Table: Accepted values by property group | Property group | Values | |---|---:| | invariant reaction | 6 | | phase transition | 6 | Convex hulls: [Materials Project DFT hull](https://data.orchid-project.org/hulls/dft-mp/C/C-FE.json) · [OQMD DFT hull](https://data.orchid-project.org/hulls/dft-oqmd/C/C-FE.json) · [CALPHAD hull FeC-10Hal](https://data.orchid-project.org/hulls/calphad-sgte/C/C-FE--FeC-10Hal.json) · [CALPHAD hull FeC-14Nar-3g](https://data.orchid-project.org/hulls/calphad-sgte/C/C-FE--FeC-14Nar-3g.json) · [CALPHAD hull FeC-16Goh](https://data.orchid-project.org/hulls/calphad-sgte/C/C-FE--FeC-16Goh.json) · [CALPHAD hull FeC-19Che](https://data.orchid-project.org/hulls/calphad-sgte/C/C-FE--FeC-19Che.json) · [CALPHAD hull FeC-19Mie](https://data.orchid-project.org/hulls/calphad-sgte/C/C-FE--FeC-19Mie.json) · [CALPHAD hull FeC-20Sae](https://data.orchid-project.org/hulls/calphad-sgte/C/C-FE--FeC-20Sae.json) · [CALPHAD hull FeC-23Jac](https://data.orchid-project.org/hulls/calphad-sgte/C/C-FE--FeC-23Jac.json) · [CALPHAD hull FeC-85Gus-LB](https://data.orchid-project.org/hulls/calphad-sgte/C/C-FE--FeC-85Gus-LB.json) ## Invariant reactions (literature) Table: Invariant reactions reported in the literature for the C–Fe system (6) | T (K) | Reaction / phases | Compositions (mole fraction) | Class | Source | Location | Quote | |---:|---|---|---|---|---|---| | 1768.15 | peritectic: L + α -> γ | | unspecified | [1] Kumar 1991 | Table 7, p. 6, row 2; `ORC-JKU2STKH6J` | | | 1630.15 | peritectic: L + gr -> κ | | unspecified | [1] Kumar 1991 | Table 7, p. 6, row 3; `ORC-4EO7CTA4XH` | | | 1601.15 | eutectic: L -> α + κ | | unspecified | [1] Kumar 1991 | Table 7, p. 6, row 4; `ORC-OLKGHY3WWW` | | | 1488.15 | peritectic: L + α -> ε | | unspecified | [1] Kumar 1991 | Table 7, p. 6, row 10; `ORC-BMCMQKCTB3` | | | 1427.15 | eutectic: L -> γ + gr | | unspecified | [1] Kumar 1991 | Table 7, p. 6, row 17; `ORC-5W5B2N3BG4` | | | 1011.15 | other: γ -> α + gr | | unspecified | [1] Kumar 1991 | Table 7, p. 6, row 23; `ORC-RMLP3HINPZ` | | ## Other properties ### Phase transition (6) Table: Phase transition, C–Fe system | Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote | |---|---:|---:|---|---|---|---|---| | Phase transition | 470 K | 470 | other | model | [2] Naraghi 2014 | p. 9; `ORC-VIZLL4AYSB.3a60ca` | “The intersection of the lines for cementite and Hägg carbide defines the triple point between α/χ/θ below which Hägg carbide is more stable than cementite. Similarly the intersection of the Hägg and eta carbides gives the α/η/χ triple point below which eta carbide is more stable than Hägg carbide. In the present evaluation these points are located at 720 K and 470 K respectively according to the…” | | Phase transition | 483 K | 483 | magnetic | experimental | [2] Naraghi 2014; _cites Umemoto 2001_ [doi](https://doi.org/10.1016/s1359-6462%2801%2901016-8) | p. 3; `ORC-HEP4Y2PDNK` | “Cementite has an orthorhombic crystal structure with a ferromagnetic transition around 483 K \[29\].” | | Phase transition | 485 K | 485 | magnetic | model | [2] Naraghi 2014 | p. 3; `ORC-U4T5XE5YD4` | “Due to the similarities of orthorhombic and fcc structures, p is selected as 0.25 for cementite as well, TC is set to 485 K and 〈β 〉θ is fitted to the experimental heat capacity data.” | | Phase transition | 520 K | 520 | magnetic | experimental | [2] Naraghi 2014; _cites Cohn 1953_ [doi](https://doi.org/10.1063/1.1698884) | p. 3; `ORC-OZLEXOYISG` | “Hägg carbide also appears to be ferromagnetic with a Curie temperature around 520 K \[36\].” | | Phase transition | 653 K | 653 | magnetic | experimental | [2] Naraghi 2014; _cites Cohn 1953_ [doi](https://doi.org/10.1063/1.1698884) | p. 3; `ORC-AZATUNJBME` | “ε=η-Fe2 C carbide also appears to have ferromagnetic properties for which Cohn and Hofer \[36\] gave a Curie temperature around 653 K.” | | Phase transition | 720 K | 720 | other | model | [2] Naraghi 2014 | p. 9; `ORC-VIZLL4AYSB.25c2dd` | “The intersection of the lines for cementite and Hägg carbide defines the triple point between α/χ/θ below which Hägg carbide is more stable than cementite. Similarly the intersection of the Hägg and eta carbides gives the α/η/χ triple point below which eta carbide is more stable than Hägg carbide. In the present evaluation these points are located at 720 K and 470 K respectively according to the…” | ## Sources Reporting papers the values were read from (a value cited from another work names that work in its row). 1. K. C. Hari Kumar, V. Raghavan, A Thermodynamic Analysis of the Al-C-Fe System, JPE 12, 275-286 (1991). [doi:10.1007/bf02649916](https://doi.org/10.1007/bf02649916) 2. Reza Naraghi, Malin Selleby, John Ågren, Thermodynamics of stable and metastable structures in Fe–C system, Calphad 46, 148-158 (2014). [doi:10.1016/j.calphad.2014.03.004](https://doi.org/10.1016/j.calphad.2014.03.004) ## Please cite - R. Arróyave, J. Saal, D. Shin, ORCHID-Values: thermodynamic and phase-equilibrium values read from the literature (version 2026.10; Version 1, machine-extracted), Zenodo (2026). https://doi.org/10.5281/zenodo.23735569 - R. Arróyave, J. Saal, D. Shin, ORCHID-Hulls: binary convex hulls (Materials Project, OQMD, assessed CALPHAD) (version 2026.10), Zenodo (2026). https://doi.org/10.5281/zenodo.23735891 - R. Arróyave, J. Saal, D. Shin, ORCHID data: umbrella record of the ORCHID datasets (version 2026.10; Version 1, machine-extracted), Zenodo (2026). https://doi.org/10.5281/zenodo.23736065 Also cite the original source of every value you use (paper_citation / paper_doi, and cited_dois for values the paper cites from earlier work); A. Jain et al., The Materials Project: A materials genome approach to accelerating materials innovation, APL Materials 1 (2013) 011002, https://doi.org/10.1063/1.4812323 (CC BY 4.0); J. E. Saal et al., JOM 65 (2013) 1501, https://doi.org/10.1007/s11837-013-0755-4 and S. Kirklin et al., npj Comput. Mater. 1 (2015) 15010, https://doi.org/10.1038/npjcompumats.2015.10 (CC BY 4.0); B. Hallstedt, The SGTE collection of binary datasets, Calphad 89 (2025) 102833, https://doi.org/10.1016/j.calphad.2025.102833 (CC BY 4.0), and the original assessment named in each file. Version 1, machine-extracted: values were read by language-model readers constrained to quote their source and checked automatically, and the release was then audited on the printed pages by adversarial audits, an independent second review of fit-facing records and a preliminary human review of a frozen sample. Flags such as accepted and ESPEI-ready record screening results, not certification; known issues are listed in the release notes. ```bibtex @misc{orchid_literature_2026, author = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon}, title = {{ORCHID-Values: thermodynamic and phase-equilibrium values read from the literature}}, version = {2026.10}, publisher = {Zenodo}, year = {2026}, doi = {10.5281/zenodo.23735569}, url = {https://doi.org/10.5281/zenodo.23735569}, note = {Version 1, machine-extracted} } @misc{orchid_hulls_2026, author = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon}, title = {{ORCHID-Hulls: binary convex hulls (Materials Project, OQMD, assessed CALPHAD)}}, version = {2026.10}, publisher = {Zenodo}, year = {2026}, doi = {10.5281/zenodo.23735891}, url = {https://doi.org/10.5281/zenodo.23735891} } @misc{orchid_data_2026, author = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon}, title = {{ORCHID data: umbrella record of the ORCHID datasets}}, version = {2026.10}, publisher = {Zenodo}, year = {2026}, doi = {10.5281/zenodo.23736065}, url = {https://doi.org/10.5281/zenodo.23736065}, note = {Version 1, machine-extracted} } ``` --- Derived data CC BY 4.0 ([licence](https://creativecommons.org/licenses/by/4.0/)): cite ORCHID ([CITATION.cff](https://data.orchid-project.org/CITATION.cff)) and the original sources. Quotes are short excerpts kept so that each value can be checked; they remain under the publishers' copyright and are not relicensed. Source papers, page images and full text are not redistributed. Field reference: [SCHEMA.md](https://data.orchid-project.org/literature/SCHEMA.md). Machine-readable guide: [llms.txt](https://data.orchid-project.org/llms.txt). Found an error? The report link of a value (Markdown: its id, ORC-..., in the Location column) opens a pre-filled GitHub issue, https://github.com/orchid-calphad/orchid-data/issues/new?template=report-value-error.yml&record_id=\, carrying only the record id, source and value; [how to contribute](https://orchid-project.org/contribute/).