铜包钢复合线的制备及其组织性能的研究

发布时间：2018-05-05 09:20

  本文选题：铜包钢复合线 + 力学性能　； 参考：《江西理工大学》2016年硕士论文

【摘要】：高速铁路是现代社会发展中的新型运输模式,它的兴起迎合了当前世界各国交通发展的需要,并发展十分迅速。高铁接触线作为高铁中最重要的部分,其质量好坏决定了高铁运行的稳定性及安全性。铜包钢复合线具有良好导电性、高强度、耐腐蚀、寿命长等优点,在接触线领域有很大的应用前景。本文通过拉伸复合法及水平连铸法制备铜包钢线,对其进行冷变形及退火处理,分析了复合线的横、纵截面金相组织变化、扩散层厚度、界面结合强度、铜-钢界面显微硬度、抗拉强度、延伸率和导电率。探索了拉拔变形工艺、退火工艺对其组织及性能的影响规律。自主设计开发了水平连铸铜包钢线坯装置,该装置可连续制备出Φ12mm铜包钢线坯,其界面扩散层厚度为2.5μm,界面结合强度为29.5MPa。此外,采用拉伸复合法制得Φ7mm铜包钢线坯。对铜包钢线进行冷拉变形,随变形量的增大,拉拔变形后Cu、Fe的横截面组织均呈现晶界模糊,纵截面组织均呈现纤维状。在退火过程中,随退火温度的升高及时间的增加,Cu、Fe横、纵截面晶粒增大。相比退火时间,退火温度对组织的影响更明显。拉拔变形中随拉拔变形量的增大,铜包钢复合线的导电率、延伸率降低,抗拉强度升高。随退火温度的提高及时间的增加,延伸率升高,抗拉强度降低。导电率随退火时间的延长而升高,随温度的升高先上升后下降。随变形量的增大,铜、钢的显微硬度增大。退火后铜、钢的显微硬度显著下降,随退火温度的升高及退火时间的延长,距离界面同一位置处铜、钢的显微硬度逐渐下降。随退火温度升高和退火时间的增加,扩散层厚度变厚,界面结合强度增加。到达Fe的再结晶温度后,温度再升高、时间再增加,扩散层厚度、界面结合强度基本保持不变。综合考虑其扩散层及界面结合情况,得到最佳退火工艺为750℃退火2 h。
[Abstract]:High-speed railway is a new mode of transportation in the development of modern society. High-speed contact line is the most important part of high-speed rail, its quality determines the stability and safety of high-speed rail operation. Copper clad steel composite wire has many advantages, such as good electrical conductivity, high strength, corrosion resistance, long life and so on, so it has great application prospect in the field of contact wire. In this paper, copper clad steel wire was prepared by tensile composite method and horizontal continuous casting method. The microstructure changes of transverse and longitudinal sections, diffusion layer thickness, interface bonding strength and microhardness of copper steel interface were analyzed. Tensile strength, elongation and conductivity. The influence of drawing deformation process and annealing process on the microstructure and properties were investigated. A horizontal continuous casting copper clad steel wire billet device has been designed and developed. The 桅 12mm copper clad steel wire billet can be continuously prepared by this device. The thickness of the interface diffusion layer is 2.5 渭 m and the interface bonding strength is 29.5 MPA. In addition, 桅 7mm copper clad steel wire billet was obtained by tensile compound method. The cold tensile deformation of copper clad steel wire shows that the grain boundary is blurred and the structure of longitudinal section is fibrous after drawing deformation. During annealing, the grain size of the longitudinal section increases with the increase of annealing temperature and time. Compared with annealing time, the effect of annealing temperature on microstructure is more obvious. The electrical conductivity, elongation and tensile strength of copper clad steel composite wire decrease with the increase of drawing deformation. With the increase of annealing temperature and time, the elongation increases and the tensile strength decreases. The conductivity increases with the increase of annealing time, and then decreases with the increase of temperature. The microhardness of copper and steel increases with the increase of deformation. After annealing, the microhardness of copper and steel decreased significantly. With the increase of annealing temperature and the prolongation of annealing time, the microhardness of steel decreased gradually at the same location from the interface. With the increase of annealing temperature and annealing time, the thickness of the diffusion layer becomes thicker and the interfacial bonding strength increases. After reaching the recrystallization temperature of Fe, the temperature rises again, the time increases again, the thickness of diffusion layer and the interfacial bonding strength remain unchanged. Considering the bonding of diffusion layer and interface, the optimum annealing process was obtained at 750 鈩，

本文编号：1847131