Materials Science
Iron-Carbon Phase Explorer
A thermodynamic explorer for the iron-carbon system. Vary temperature and carbon wt % to trace grain structures, crystal lattice transformations, Brinell hardness estimates, and tensile strength curves.
Material System
Iron-Carbon (Fe-C)
Binary Alloy
Key Eutectic
4.3% Carbon
1147 °C
Key Eutectoid
0.76% Carbon
727 °C
Parameters
Carbon preset classification
Temperature Cycle Playback
Thermodynamic Equations
A3 Temperature Line
T_A3 = 912 - 243.4 * wt% C (for C < 0.76%)
Acm Temperature Line
T_Acm = 727 + 304.3 * (wt% C - 0.76) (for 0.76% <= C <= 2.14%)
RT Hardness Estimate (HB)
HB = 100 + 200*C (C <= 0.8), HB = 260 + 110*(C-0.8) (0.8 < C <= 2.0)
Tensile Strength (UTS)
UTS (MPa) = 3.45 * HB
Structure: Eutectoid Steel - current carbon level of 0.80% carbon.
Lever rule: At RT, phase consists of Dynamic High-Temp Equilibrium.
Linked Thermodynamics & Grains
Interactive Fe-C Phase Diagram
Microscopic Grains
Estimated structure at 500x zoom
Selected PhaseAustenite + Cementite
Equilibrium Phase
Austenite + Cementite
Brinell Hardness
260HB
Tensile Strength
897MPa
Microconstituent Ratio
Dynamic High-Temp Equilibrium
Hardness & UTS vs Carbon Content (at RT)
Composition Hardness Correlation Table
| Carbon Content (wt%) | Est. Hardness (HB) | Est. Tensile Strength (MPa) |
|---|---|---|
| 0.00 | 100 HB | 345 MPa |
| 0.20 | 140 HB | 483 MPa |
| 0.40 | 180 HB | 621 MPa |
| 0.60 | 220 HB | 759 MPa |
| 0.80 | 260 HB | 897 MPa |
| 1.00 | 282 HB | 973 MPa |
| 1.20 | 304 HB | 1049 MPa |
| 1.40 | 326 HB | 1125 MPa |
| 1.60 | 348 HB | 1201 MPa |
| 1.80 | 370 HB | 1277 MPa |
| 2.00 | 390 HB | 1346 MPa |
| 2.20 | 401 HB | 1383 MPa |
| 2.40 | 412 HB | 1421 MPa |
| 2.60 | 423 HB | 1459 MPa |
| 2.80 | 434 HB | 1497 MPa |
| 3.00 | 445 HB | 1535 MPa |
| 3.20 | 456 HB | 1573 MPa |
| 3.40 | 467 HB | 1611 MPa |
| 3.60 | 478 HB | 1649 MPa |
| 3.80 | 489 HB | 1687 MPa |
| 4.00 | 500 HB | 1725 MPa |
| 4.20 | 511 HB | 1763 MPa |
| 4.40 | 522 HB | 1801 MPa |