材料期刊网

利用超音速微粒轰击0Cr18Ni9不锈钢试样单面获得表面纳米化，另一面保持原始晶粒。试样分别在300℃，400℃，450℃不同时间下渗氮，通过金相显微镜（OM）、X-射线衍射仪（XRD）、透射电镜（TEM）、扫描电镜（SEM）和硬度测定分析表层显微组织和性能变化。结果表明，经SFPB处理，样品表层形成约200μm的变形区，变形以孪生为主要方式；对比发现表面纳米化预处理可以成倍提高渗层的厚度，大大改善了金属表面的硬度分布梯度。

One side of 0Cr18Ni9 stainless steel plate was nanocrystallized by Supersonic Fine Particles Bombarding (SFPB), but the other side remained original coarse-grained condition. The samples were nitridized respectively at 300℃、400℃、450℃ for different time. The microstructure and property evolution of these nitridized samples was characterized by using metallographical microscope(OM)、X-ray diffraction(XRD)、transmission electron microscope (TEM)、scan electron microscope (SEM) and examination of microhardness. The results show that the samples surface after SFPB occur transformation layer of about 200μm and has nanocrystallization of 10μm at the top surface; surface nanocrystallization pre-treatment can enhance the thickness of nitriding layer. The metal surface’s distribution of hardness is greatly improved.