The fe-c and al-fe-c systems were investigated over the range of 1550 deg c to 2300 deg c by chemical analysis of alloys saturated with carbon within internally sealed graphite crucibles. The solubility of carbon in liquid iron agrees with accepted published values at 1550 deg c, but was found to be slightly higher than published values at higher temperatures. Partial isothermal sections for the al-fe-c system at 1,550 deg c, 2,150 deg c, and 2,300 deg c and complete isothermal sections at 1,700 deg c, 1,850 deg c, and 2,000 deg c were constructed from the chemical analyses and from metallographic observations. The univariant point on each complete isotherm, at which the solid phase in equilibrium with the homogeneous liquid changes from al4c3(aluminum carbide) to carbon with increasing fe-al ratio in the alloy, was determined to be 55.0Al-37.6Fe-7.4C at 1,700 deg c, 61.2Al-29.4Fe-9.4C at 1,850 deg c, and 65.7Al-21.9Fe-12.4C at 2,000 deg c, where all concentrations are in atomic percent. The only solid phases observed at these elevated temperatures were al4c3 and graphite.