鐵—鉻—錳奧氏體合金輻照誘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奧氏體合金,經電子線輻照后析出相—基體相界面誘起溶質原子偏析行為。實驗結果表明:合金中析出相為富Cr的M₂₃C₆型碳化物。晶內析出相經輻照相界面處Cr的濃度增加,Mn的濃度降低。而晶界上和晶界近傍析出相的相界面Cr的濃度降低。合金元素Cr濃度的不同變化是與輻照誘起晶界偏析機構改變有關。
本文對此現象,應用輻照誘起晶界偏析理論,提出兩種偏析機構的模型,較好的解釋上述實驗結果。

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.