溶质原子向晶界的非平衡偏聚机制

MECHANISM OF NON-EQUILIBRIUM SEGREGATION OF SOLUTE TO GRAIN BOUNDARIES

本文以空位-溶质原子拖曳机制为基础,并考虑了空位、溶质原子和复合体三者的反应平衡及晶界平衡偏聚的作用,得到了溶质原子的非平衡晶界偏聚动力学方程。对硼在奥氏体中等温及连续冷却时所产生的非平衡晶界偏聚现象进行了理论计算,得到了与实验较为一致的结果。

In consideration of the local equilibrium among vacancies, solute atomsand vacancy-solute atom complexes, and the influence of equilibrium grain bound-ary segregation, theoretical dynamic formulas for non-equilibrium grain boundarysegregation of solute have been derived on the basis of the vacancy-draggingmechanism. Theoretical calculation by computer has been carried out for the non-equilibrium segregation of B to austenitic grain boundaries during isothermal hold-ing and continuous cooling after heating at high temperatures. The results agree wellwith those obtained from experiments.