中文摘要：

采用超声速微粒轰击技术对0Cr18Ni9Ti不锈钢和16MnR合金钢焊接接头进行表面纳米化处理，利用金相显微镜、透射电镜和X射线衍射对材料表面的微观组织和表层结构进行分析与表征，并利用显微硬度仪对硬度沿厚度方向的变化进行分析。结果表明：经超声速微粒轰击处理后，0Cr18Ni9Ti不锈钢和16MnR合金钢两种焊接接头的晶粒尺寸由里及表逐渐减小，据表层70gm处，晶粒尺寸平均分别为94．8、89．4nm，样品表层晶粒尺寸平均分别为22、20nm：0Cr18Ni9Ti不锈钢和16MnR合金钢焊接接头表层硬度分别提高至570HV及470HV左右，是内部硬度的2倍以上。母材、热影响区、焊缝三个区域的硬度在表层趋于一致，表层组织得到均一化。

英文摘要：

A nanocrystalline surface layer is fabricated on 0Crl8Ni9Ti stainless steel and 16MnR low alloy steel welded joint by using a supersonic particles bombarding（SSPB） technology. The microstructure and surface structure of the material surface are analyzed by means of metalloscope, transmission electron microscope and X-ray diffraction. The hardness variation along the depth of the treated sample is examined as well. It is showed that after the SSPB treatment for a short time, the initial coarse-grained structure in the top surface layer is refined, and the average crystal dimension is 22 nm and 20 nm. The surface structure is homogeneous. At the same time, the hardness of nanostructured surface layer is enhanced significantly after the SSPB treatment. Compared with the core, the surface layer hardness enhances at least two times.