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用PTA方法研究了Fe-30％Ni合金中硼在晶界的偏聚行为。实验表明在550-1200℃保温后用不同方式冷却的试样中存在平衡与非平衡两类硼偏聚,它们各自的形成机制不同,试验条件对它们的影响不同。平衡偏聚在保温时形成,在低温区淬火时起主要作用。在高温加热后,用通常冷却速度淬火时,晶界偏聚主要来源于冷却过程中产生的非平衡偏聚,实际瘁火试样中观察到的硼偏聚是这两类偏聚的叠加。试验指出,Fe-30％Ni合金中偏聚方式有一个转折温度区,这温度受冷却速度影响,在通常冷却速度下,这个转折温度在650～750℃之间。
The segregation behavior of boron at grain boundaries in Fe-30% Ni alloy was studied by PTA method. Experiments show that after cooling at 550-1200 ℃, there are two types of boron segregation: equilibrium and non-equilibrium. The formation mechanism of each is different, and the influence of test conditions on them is different. Balance segregation formed in the insulation, quenching in low temperature plays a major role. After quenching at normal cooling rate, the segregation of the grain boundaries mainly originates from the non-equilibrium segregation during cooling. The segregation of boron observed in the actual test specimens is the superposition of these two types of segregation. The experiment indicates that there is a transition temperature zone in the segregation mode of Fe-30% Ni alloy, which is influenced by the cooling rate. Under the normal cooling rate, the transition temperature is between 650 and 750 ℃.