[en] In the Fe-Nd system an additional ferromagnetic phase with T_c 245± 10 deg C is found. In the ternary Fe-Nd-B system, magnetic analysis shows two ferromagnetic phases with T_c= 245 and 285 deg C in as-cast alloys, in addition to Fe₁₄ Nd₂ B. Those phases are formed through the eutectic solidification of a neodymium-rich liquid at the boron-poor side of the system, suppressing the formation of Fe₁₄ Nd₂ B. An annealing at 600 deg C dissolves the phase with T_c=245 deg C and develops Fe₁₄ Nd₂ B. This results in an H_ei increase from 3.9 k O e in the as-cast to 14.1 k O e in the annealed condition for an Fe-80 at % Nd-5 at%B alloy. This suggests that the dissolution of additional ferromagnetic phases in the intergranular regions of sintered Fe-Nd-B magnets might be the positive effect of the 600 deg C annealing. (author)