Fe-Ni-Co-Ti合金马氏体的组织形态惯习面及晶界析出物对马氏体转变的影响

Influences of Morphology and Habit-plane of the Martensite and Segregating Phase at the Grain Boundaries on the Martensitic Transformation in the Fe-Ni-Co-Ti Alloy

对经不同预处理的Fe－30.01Ni－8，97Co－2．96Ti铁基合金的马氏体的表面浮凸、组织形态、惯习面以及原奥氏体晶界析出物对马氏体转变的影响进行了分析研究。结果表明，经1200℃×30h奥氏体均匀化、700℃×9h时效的合金，其马氏体为透镜状，惯习面为｛225｝γ；经1200℃×30h奥氏体均匀化、室温时效1．7×104h的合金，其马氏体为透镜状＋薄片状，薄片状马氏体的惯习面为｛31015｝γ；原奥氏体晶界处的析出物抑制马氏体转变。

This paper deals with the effects of surface bulge, morphology and habit-plane of the martensite and segregating phase at the grain boundaries of original austensite on the martensitic transformation in the Fe-30. 01Ni-8.97Co-2. 96Ti alloy under different pre-treatments. As the alloy was austenized at 1200℃×30h and aged at 700℃×9b,the martensite in the alloy is lens-like and its habit plane is { 2 2 5 }γ. While austenized at 1200℃×30h and aged at room temperature for 1. 7 ×104h,the martensite is lens-like plus slick, the habit-plane for the slick martensite is {3 10 15 }γ.Moreover, it was found that the segregating phase at the grain boundaries retards the martensitic transformation.