【摘要】 结合试验和第一性原理计算,采用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)等方法研究了铬元素对780℃轻质Fe-Mn-Al-C钢中κ相形成的影响。研究发现:含Cr轻质Fe-Mn-Al-C钢在780℃保温2 h、1天和15天后,组织中均出现了κ相,呈棒状。在相同热处理条件下,含Cr轻质钢中κ相的粒径较小;随着保温时间的延长,κ相发生粗化,含Cr量高的轻质钢中κ相的长大趋势较小。通过第一性原理计算发现,含Cr轻质钢中κ相的形成能比不含Cr轻质钢中κ相的形成能高。因此,试验分析和第一性原理计算结果均表明,Cr元素对轻质钢中κ相的形成起一定的抑制作用。更多还原

【Abstract】 Effect of chromium element on the formation of κ phase in the lightweight Fe-MnAl-C steel at 780 ℃ was studied by means of X-ray diffraction( XRD),scanning electron microscopy( SEM) and transmission electron microscopy( TEM) combined with experiments and first-principles calculations. It was found that κ phase appeared in the light-weight Fe-Mn-Al-C steels containing Cr after holding at 780 ℃ for 2 h,1 d and 15 d,and the appearance of κ phase was rod-shaped. Under the same heat treatment conditions,the particle size of κ phase was smaller in the lightweight steel with Cr than that without Cr; and with the increase of holding time,the κ phase was coarsened,and the growth trend of κ phase became smaller in the steel with higher Cr content. It was found from first-principle calculation that the formation energy of κ phase in the lightweight steel with Cr became higher than that in the steel without Cr. Therefore,both experimental analysis and first-principle calculation results showed that the formation of κ phase in the lightweight steel was inhibited by Cr.更多还原