铁—铬—锰奥氏体合金辐照诱起相界面合金元素偏析

Radiation-Induced Segregation at Precipitate-Matrix Interface in Fe-Cr-Mn Austenitic Alloy

摘要: 研究了含有W、V的Fe-Cr-Mn奥氏体合金,经电子线辐照后析出相—基体相界面诱起溶质原子偏析行为。实验结果表明:合金中析出相为富Cr的M₂₃C₆型碳化物。晶内析出相经辐照相界面处Cr的浓度增加,Mn的浓度降低。而晶界上和晶界近傍析出相的相界面Cr的浓度降低。合金元素Cr浓度的不同变化是与辐照诱起晶界偏析机构改变有关。
本文对此现象,应用辐照诱起晶界偏析理论,提出两种偏析机构的模型,较好的解释上述实验结果。

Abstract: The radiation-induced segregation at precipitate-matrix interface in Fe-Cr-Mn austenitic alloy containing W and V was investigated by electron irradiation. The results show that the precipitates are identified as M23C6 type chromium-carbides. Cr, W and V are enriched, but Mn and Ni tend to be depleted at precipitate-matrix interface within grain.The morphology of precipitates occurred to change at and near the grain bou-boundaries, while Cr is depleted at precipitate-matrix interface.
The change of solute atom segregation behavior is directly related to segregation mechanisms.Two kinds of segregation phenomena of Cr concentration may be explained by the theory of radiation-induced segregation.