硼在体心立方Fe-3%Si合金中的晶界偏聚行为

BEHAVIOUR OF BORON SEGREGATION TO GRAIN BOUNDARIES IN BCC Fe-3%Si ALLOY

利用硼径迹显微照相(PTA)技术研究了体心立方Fe—3%Si合金试样在冷却和淬火等温过程中硼向晶界的偏聚行为结果表明:Fe-3%Si合金中硼的晶界平衡偏聚趋势高于奥氏体合金,也不存在淬火诱导硼向晶界的非平衡偏聚.硼原子与晶界结合能Q=55.7 kJ/mol用淬火诱导非平衡偏聚的复合体机制解释了硼在Fe-3%Si合金与奥氏体合金中偏聚行为异同的原因.

Behaviour of B segregation to grain boundaries in Fe-3% Si alloy has beenstudied by means of particle tracking autoradiography. Results indicate that B tends to equi-librium segregation to grain boundaries in Fe-3% Si higher than in austenitic alloys. No ob-servable nonequilibrium segregation of B to grain boundaries was revealed in Fe-3% Si alloyduring cooling and isothermal holding. The binding energy between B atoms and grainboundaries is 55.7±1.7 kJ/mol. Based on the complex mechanism of quenching-induce-nonequilibrium segregation, different behaviours of B segregation in γ-Fe and b.c.c.Fe-3% Si alloy were discussed.