摘要
以Fe-La合金为扩散偶,对稀土镧在纯铁奥氏体晶界的扩散行为进行研究。采用Gleeble-1500D热模拟机完成γ-Fe区系列扩散焊接试验,借助扫描电镜观察显微组织,并利用能谱仪进行成分测定及分析。在此基础上,根据相应的扩散公式计算稀土La在γ-Fe区的扩散系数与扩散激活能。结果表明,晶界是La在铁基体中的主要扩散路径。温度越高,稀土La在晶界处越容易扩散。1000、1050、1100和1200℃时La在纯铁奥氏体晶界的扩散系数分别为2.806×10^（-14）、3.297×10^（-14）、1.469×10^（-13）和2.452×10^（-13）m^2/s。La在γ-Fe晶界的扩散系数公式为D=4.3×10^（-8）exp（-119 000/RT）。
Diffusion behavior of lanthanum in the austenitic grain boundary of pure iron was investigated based on the Fe-La alloy diffusion couples. Diffusion bonding of γ-Fe phase region was conducted by Gleeble-1500 D thermal simulation machine,microstructure was observed through scanning electron microscope,and the composition was determined and analyzed by means of EDS. Based on this,calculation formulas were carried out to obtain the diffusion coefficient and the activation energy for diffusion of lanthanum in the γ-Fe grain region. The results show that the grain boundaries are main diffusion paths of lanthanum in iron matrix. The higher the temperature,the easier diffusion of lanthanum along grain boundaries. The diffusion coefficients of lanthanum in the austenitic grain boundary of pure iron are calculated as 2. 806 × 10^（-14）,3. 297 × 10^（-14）,1. 469 × 10^（-13） and 2. 452 × 10^（-13） m^2/s at 1000,1050,1100 and 1200 ℃,respectively. The diffusion coefficient formula of lanthanum in γ-Fe boundary is calculated as D = 4. 3 × 10^（-8） exp（-119 000/RT）.
出处
《金属热处理》
CAS
CSCD
北大核心
2018年第1期38-42,共5页
Heat Treatment of Metals
基金
国家自然科学基金(51101083)
内蒙古重大基础项目(201503001-4-2)
关键词
镧
γ-Fe
晶界
扩散系数
lanthanum
γ-Fe
grain boundary
diffusion coefficient
