超低碳微合金钢中硼的偏聚

Segregation of Boron in Ultralow-carbon Micro-alloy Steels

用硼径迹显微照相技术研究了超低碳微合金钢从1150℃以5℃/s冷却到850℃过程中硼晶界偏聚的形成与发展过程,测量了不同温度时硼富集因子与贫化区宽度,分析了铜元素对硼晶界偏聚的影响。结果表明:在冷却初始阶段,晶界硼偏聚量迅速增加,在1000℃左右达到最大值后,随着温度的降低,硼晶界偏聚量开始逐渐减少,在910℃左右达到最小,温度继续降低,晶界上硼的偏聚量又开始增加。实验结果还表明添加铜元素能促进硼向晶界的偏聚。

By means of Particle Tracking Autoradiography（PTA）, the segregation of boron to grain boundaries in ultralow carbon micro-alloy steels during cooling from 1150℃ to 850℃ at 5℃/s was in- vestigated. The enrichment factors and widths of boron depletion zone were measured at different temperatures, and the effect of copper on the segregation of boron was analyzed. The results show that the concentration of boron at the grain boundary increases and reaches its maximum at about 1000℃ at the beginning of the cooling; after that, it decreases gradually to a minimum with tempera- tures decreasing to 910℃ ; and then, it increases again. Experiments also indicate that the segregation of the boron could be enhanced via adding copper.