In order to improve the surface strength of SCX400 wheel steel, ultrasonic rolling technology was used to strengthen the surface. The pressure parameters were optimized by means of experimental test. Results showed that increasing the ultrasonic rolling pressure was helpful to obtain the deformation layer with larger thickness. There was a strong plastic deformation in the tissue near the surface, and the deformation degree in the transition zone was decreased, while the internal microstructure remained basically unchanged. Nanocrystals with a size of about 5 nm were formed in the surface tissues when 100 N ultrasonic rolling was applied. As the rolling pressure continued to increase to 400 N, a higher proportion of amorphous microstructure was obtained on the surface of the sample. The surface hardness of SCX400 wheel steel was decreased as a whole with the increase of depth. When the rolling pressure was increased to 300 N and 400 N, the microhardness of the area 50 μm from the surface was 371 HV and 383 HV, respectively. The residual compressive stress of surface layer was increased continuously with the increase of ultrasonic rolling pressure. In the process of increasing the rolling pressure, the depth of residual stress was also increased significantly. After the completion of ultrasonic rolling, the microstructure lattice of the alloy was changed, and the compressive residual stress was formed.

为了促进Sn-Cu-Sb涂层在轴瓦涂层表面的应用,通过激光熔覆技术在燃气轮机用0Cr1 1Ni2Mo马氏体不锈钢表面制备Sn-Cu-Sb涂层,并对涂层的显微组织结构与不同区域的元素含量进行了表征,同时观察了拉伸断口部位的微观形貌.结果 表明:不锈钢基体中主要存在铁素体与马氏体,Sn-Cu-Sb涂层内形成了众多弥散分布状态的方块状物.在Sn-Cu-Sb涂层内主要存在锡基固溶体以及Cu6Sn5、SnSb等金属间化合物成分.Sn-Cu-Sb涂层和不锈钢之间形成了一条明显的中间界面过渡层,涂层以冶金方式和不锈钢基体进行结合.在断口部位形成了众多的凹坑与方块状物,还存在许多深度较浅的韧窝,Sn-Cu-Sb涂层/不锈钢的断口是发生准解理过程形成的.

随着经济的发展,能源在经济发展中占据着越来越重要的地位,而在环境保护的发展规划下,清洁型能源的开发与推广成为了新的研究话题.而风力发电在当前作为最成熟、最具规模化的可再生能源的利用形式受到了世界各国的关注.本文先对垂直轴风力发电机和液压传动技术的发展现状进行了研究,再对液压传动型垂直轴风力机组的仿真模型进行了分析,最后通过相关的实验来展现此种风力机的优良性能.

分析了线切割加工过程中图纸、电极丝选择、穿丝孔位置、加工参数选择及工作液选择中的原则和注意事项,详细列举、分析了线切割加工过程中容易出现的断丝现象和原因,对线切割加工过程工艺的设置具有一定的参考意义.

针对传统铣削方法加工圆柱凸轮所产生的一些问题,提出了一种针对槽宽大于刀具直径的圆柱凸轮槽的数控铣削加工方法。通过分析研究,建立了一种正确的坐标转换模型,并依此加工出符合要求的宽槽圆柱凸轮。