添加铌氮的铁基高温合金晶界相分析

Intergranular Precipitate Analysis for Niobium and Nitrogen Bearing Ferrous High Temperature Alloy

用透射电镜（ＴＥＭ）和扫描电镜（ＳＥＭ）观察到添加ＮｂＮ的铁基高温合金晶界上主要相是厚片状和小片状Ｍ６Ｃ碳化物，分子式组成为Ａ４Ｂ２Ｃ。而晶界上是以Ｍ６Ｃ为核并与之保持共格的Ｍ２３Ｃ６，以薄片或薄膜单晶形式长大，从波纹图样上测得它们之间的错配度为３％。

The intergranular precipitates existed in niobium and nitrogen bearing ferrous high temperature alloy are studied by TEM and SEM. The main substances have been proved to be the thick lamellar and small plate like M 6C carbide with chemical formula of A 4B 2C. The M 23 C 6, with M 6C as its nucleus and colatticed with M 6C, is on the grain boundary and grows in the form of thin lamellar and filmy single crystal. The misfit between M 23 C 6 and M 6C obtained from the moire pattern is about 3%.