高能喷丸0cr18ni9ti 不锈钢自纳米化机理 - 中南大学学报.pdf

第 40 卷第 3 期 中南大学学报( 自然科学版) Vol.40 No.3 2009 年 6 月 Journal of Central South University (Science and Technology) Jun. 2009 高能喷丸0Cr18Ni9Ti 不锈钢自纳米化机理 韩 靖，盛光敏，胡国雄 (重庆大学 材料科学与工程学院，重庆，400044) 摘 要：为在 0Cr18Ni9Ti 不锈钢棒材端面制备出纳米晶，采用高能喷丸(HESP)对不锈钢棒材的端面进行表面自 纳米化处理。利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X 射线衍射仪对喷丸端塑性变形层不同深度 的组织进行表征，并对0Cr18Ni9Ti 不锈钢在高能喷丸过程中的晶粒细化机理进行讨论。结果表明：在喷丸端大约 70 μm 深度内形成纳米组织，其中喷丸表面的晶粒尺寸达到 52 nm 左右。晶粒细化机理为：在小应变作用下主要 是孪生变形把粗大晶粒细化成孪晶薄片，在大应变作用下，孪晶交叉把孪晶片细化成纳米晶粒，同时在孪晶交叉 处产生应变诱导马氏体相变。 关键词：高能喷丸；0Cr18Ni9Ti 不锈钢；孪生变形；纳米晶 中图分类号：TG142.1+ 1 文献标识码：A 文章编号：1672−7207(2009)03−0644−06 Self-nanocrystallized mechanism for 0Cr18Ni9Ti by means of high energy shot peening HAN Jing, SHENG Guang-min, HU Guo-xiong (College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China) Abstract: In order to prepare nanograins on the end face of 0Cr18Ni9Ti stainless steel bar, the end face was treated by means of high energy shot peening (HESP). The microstructures of plastic deformation layer were characterized by scanning electron microscopy(SEM), transmission electron microscopy(TEM), and X-ray diffraction(XRD). The grains refinement mechanism was analyzed and discussed. The results show that nanograins with about 52 nm of diameter form on the top surface, and the thickness of nanomicrostructures is about 70 μm. In the course of refinement of coarse grains, the twinning deformation transforms a grain into twin lamellae structure under small strain, multi-twinning deformation refines lamellae into nanograins under high strain. At