GH128铸态合金中硼的分布

The Distribution Search of Boron in Alloy GH128

采用高分辨率的径迹显微照相技术,研究了GH128铸态合金中硼的偏析和在均匀化、正火、调质热处理过程中硼分布的变化,并且分析了硼含量、加入稀土元素以及合金中Mo等元素对硼分布的影响．硼在铸态合金中有明显的偏析现象,并随着硼含量的增加而偏析加剧,经过常规的均匀化处理之后,铸态合金中硼分布状态受Mo偏析的影响非常显著．在一定的条件下,硼相沿着奥氏体的特定结晶学平面析出,或结晶界形成粗大连续网状的硼相,从而导致沿晶界的脆性断裂,实验表明稀土元素有保护硼的良好作用．

The segregation and distribution of Boron varied with heat-treatment and homogenization in the casting alloy GH128 have been investigated by the high resolution microphotography of track. There is strong Boron＇s segregation, and it becomes more strongly with more Boron elements. After normal homogenization, the distribution of Boron may be strongly affected by the segregation of Mo. Under certain condition, the Boron beating phases may precipitate either along certain austenite planes or at the grain boundaries to form coarse continuous net works, the cause brittle fracture. The results also showed that rare earth elements might act as good protective additions for Boron.