【摘要】 采用正电子湮没技术结合透射电镜，考察了Ｔｉ含量对一种Ｆｅ－Ｎｉ－Ｃｏ基合金的微观结构及氢脆敏感性的影响结果表明：改变合金的Ｔｉ含量，会使合金中第二相的尺寸、数量、分布及种类发生变化，合金的强度、塑性及氢脆敏感性均随之发生改变；大尺寸的γ′颗粒及η相与基体间的界面是一种较强的缺陷，可以促进氢的局部聚并，从而导致合金氢脆敏感性的升高研究表明，合金的氢脆敏感性与合金强度之间并不存在必然的联系，而是取决于合金的微观结构，即随着合金中利于氢原子局部聚并的缺陷浓度的升高而增大更多还原

【Abstract】 Positron annihilation,TEM,SEM and high purity high pressure hot charging of hydrogen have been used to investigate the effect of microstructure,changed by varying of Ti content, on the hydrogen performance of the Fe-Ni-Co based alloys.It was found that the interface between the strengthening phase γ′with large size and the matrix was a kind of relative strong defect, which could accelerate the local accumulation of hydrogen. As a result, when the size of intragranular γ′particles is large, very fine dimples can be observed on the fracture surface of hydrogen charged specimens, and hydrogen-induced intergranular fracture can occur when large γ′particles precipitate at grain or twin boundaries.However,if the size of γ′ is small. the interface of γ-γ′is very weak defect and no intergranular fracture occurs even the γ′ particles precipitate at grain or twin boundaries. The interface between the stable phase η,with hop structure, and the matrix was also found to be strong defect. When the η phase precipitates at grain boundaries, hydrogen-induced intergranular fracture could happen, and when η phase formed within grains, hydrogen induced second cracks could be found on the fracture surface. In the present work, the alloy with medium Ti content is relatively good at resisting hydrogen embrittlement because the size and distribution of γ′are homogeneous and no stable phase is formed,while the hydrogen performance of the alloys with higher or lower content of Ti becomes bad lust because the defect density and intensity in these alloys are high.更多还原