磷的非平衡晶界偏聚恒温动力学实验及计算研究

Experimental study on non-equilibrium grain-boundary segregation isothermal kinetics of phosphorus and kinetics calculation

选用12Cr1MoV工业用钢,通过俄歇电子能谱分析方法(AES),对磷在1050℃固溶处理温度下,540℃恒温时效过程中的非平衡晶界偏聚浓度进行了测试,在国际上首次获得了磷在钢中的非平衡晶界偏聚动力学完整曲线,该曲线直接验证了由徐庭栋提出的非平衡晶界偏聚动力学理论模型.论文还进行了非平衡晶界偏聚动力学计算,求出了12Cr1MoV钢在540℃恒温过程中复合体的扩散系数Dc及磷原子的自扩散系数Di,并应用非平衡晶界偏聚动力学方程进行了动力学曲线模拟,拟合曲线与实验曲线符合完好.证实了非平衡晶界偏聚的空位-溶质原子复合体扩散机制.

The non-equilibrium grain-boundary segregation (NGS) level of phosphorus with solution temperature 1050℃ at isothermal holding temperature 540℃, in an industrial steel 12Cr1MoV, was measured with Auger Electron Spectroscopy (AES). For the first time known, an NGS kinetics complete curve of phosphorus is given, which provides direct evidence of the NGS kinetic model proposed by Xu Tingdong. Kinetics calculation was also produced in this paper. The diffusion coefficient of complexes, D_c, and diffusion coefficient of phosphorus, D_ i,were calculated, and the simulation using the kinetic equations of NGS is in good accordance with the experimental observation. The NGS diffusion mechanism of vacancy-solute atom complexes is proved out.