The relationship between the temperature of the start, peak and finish of conventional disproportionation and recombination, in hydrogen, reactions and the low starting hydrogen pressure of 10, 20, 30, 40, 50, 60, 70 and 80 kPa and maximum processing temperature of 950–1015 °C was studied by DTA and X-ray diffraction measurements for 10 g of (Nd,Pr)-Fe-B ferromagnetic powder batches. It was shown that the starting temperature of the disproportionation reaction increases when hydrogen pressure decreases. A similar dependence took place for finishing temperature of the disproportionation when pressure was in the range of 40–80 kPa. At a hydrogen pressure of 10–30 kPa, finishing temperature of the disproportionation decreased with decreasing of pressure. The temperature of the recombination reaction in hydrogen increased with increasing of the hydrogen pressure. The non-equilibrium pressure–composition–temperature schema with four zones for the (Nd,Pr)-Fe-B alloy–hydrogen system was built. The remnants of the (Nd,Pr)₂Fe₁₄B phase and disproportionation products – (Nd,Pr)H_2±x, α-Fe and Fe₂B were in zone I – zone of the disproportionation reaction and in zone II – interstitial zone. The recombined (Nd,Pr)₂Fe₁₄B phase, (Nd,Pr)H_0–2±x, α-Fe and Fe₂B phases were in the zone III – zone of the recombination reaction. And the (Nd,Pr)₂Fe₁₄B phase, recombined in hydrogen, existed in the zone IV – zone of the existence of (Nd,Pr)₂Fe₁₄B phase.

氢气中常规歧化和重组反应的开始、峰值和结束温度与低起始氢气压力 10、20、30、40、50、60、70 和 80 kPa 和最高处理温度之间的关系通过 DTA 和 X 射线衍射测量对 10 g (Nd,Pr)-Fe-B 铁磁粉末批次进行了研究，研究了 950–1015 °C。结果表明，当氢气压力降低时，歧化反应的起始温度升高。当压力在 40-80 kPa 范围内时，歧化的完成温度也存在类似的依赖性。在氢气压力为 10~30 kPa 时，歧化结束温度随着压力的降低而降低。氢气中复合反应的温度随着氢气压力的增加而升高。建立了(Nd,Pr)-Fe-B合金-氢体系的四区非平衡压力-成分-温度方案。(Nd,Pr) 的残余物₂ Fe ₁₄ B 相和歧化产物——(Nd,Pr)H _2±x、α-Fe 和 Fe ₂ B 位于 I 区——歧化反应区和 II 区——间隙区。重组的(Nd,Pr) ₂ Fe ₁₄ B 相、(Nd,Pr)H _0-2±x、α-Fe 和Fe ₂ B 相处于重组反应的第三区——区。并且(Nd,Pr) ₂ Fe ₁₄ B相在氢中复合，存在于IV区——(Nd,Pr) ₂ Fe ₁₄ B相存在区。