摘要
采用粉末包埋法对Cr18Ni9奥氏体不锈钢表面进行渗硅处理后,除获得致密的渗硅层外,还观察到脆性很大的高硅相。应用SEM电镜分析、能谱分析和场发射高分辨率扫描电镜等方法分析了渗硅层的成分、组织和形貌,以及渗层表面脆性相的形成及其原因。分析表明,Cr18Ni9钢渗硅层中脆性相出现在含硅量20%(原子分数)以上,其脆性源于冷却过程中高硅相周边调幅分解产物的强力约束和DO3有序相晶格常数的持续减小。
A fine and dense siliconized layer was obtained on the Cr18Ni9 austenitic steel by pack cementation, but brittle phases with high silicon content were also observed. Using the SEM analysis and the energy diffraction spectrum analysis （EDS） , and the high resolution field emission scanning electronic microscope, the composition, microstructures and their morphologies, formation of the brittle phases and its cause in the siliconized layer were all analyzed. The experimental results indicate that the brittle phases will exist in the siliconized case of Cr18Ni9 stainless steel when silicon content is over 20 at% , and that the embrittlement of high silicon phase will result from the strong constraint of spinodal decomposition product around it and the consecutive reduction of lattice constant of DO3 ordered phase during cooling of the pack cementation process.
出处
《热处理》
CAS
2008年第3期36-39,共4页
Heat Treatment
