激光熔覆工作台的设计及其工艺性能实验研究

发布时间：2018-04-27 22:42

本文选题：锅炉管 + 激光熔覆　；参考：《华北电力大学(北京)》2014年硕士论文

【摘要】：循环流化床锅炉因其具有燃烧效率高、燃料适应性广、节能环保等一系列优点,在我国的火力发电行业中占据着重要的地位。水冷壁管的高温磨损一直是循环流化床锅炉运行中普遍存在的重要问题,磨损不仅造成电厂巨大的经济损失,而且易发生因水冷壁突发性爆管而非正常停炉的重大安全事故。激光熔覆技术具有能量密度高、稀释率低、熔覆层与基体冶金结合、对工件热影响极小等优点,在工业中得到了愈来愈广泛应用。但在火电厂锅炉四管防磨技术方面,激光熔覆技术的研究和应用还甚少。本文基于Nd:YAG固体激光器的工作特性,系统设计了管道熔覆工作台,该工作台主要包括电机、变速器、控制模块、防变形装置等部分。设计了锅炉管防变形装置,基于一维杆件模型,分析了锅炉管在防变形杆件预应力作用下的应力与位移的关系,并将理论结果与数值模拟结果进行了比较。实验表明,管道熔覆平台设计合理,参数稳定；锅炉管定位准确,拆卸较为灵活,可实现对6m长锅炉管的连续熔覆。利用自行设计的激光熔覆系统,研究了不同工艺参数所制备Cr3C2-NiCr熔覆层的特性。结果表明,在最佳参数下,熔覆层厚度可达lmm,熔覆层致密、与基体材料呈冶金结合。对耐磨锅炉管取样进行熔覆层硬度分析表明,在距离表面700μm以内的位置,显微硬度在1000-1150HV范围。对熔覆层的XRD分析表明,熔覆层的主要相为Cr3C2、Cr7C3、NiCr。
[Abstract]:Circulating fluidized bed boiler (CFB) has a series of advantages such as high combustion efficiency, wide fuel adaptability, energy saving and environmental protection, which plays an important role in thermal power generation industry in China. The high temperature wear of water wall tube is always an important problem in circulating fluidized bed boiler operation. It not only causes huge economic loss in power plant, but also leads to serious safety accidents caused by sudden tube explosion of water wall instead of normal shutdown. Laser cladding technology has been widely used in industry because of its advantages of high energy density, low dilution rate, combination of cladding layer with matrix metallurgy and minimal thermal effect on workpiece. However, the research and application of laser cladding technology are few. Based on the working characteristics of Nd:YAG solid-state laser, a pipe cladding table is designed in this paper, which includes motor, transmission, control module, anti-deformation device and so on. The anti-deformation device of boiler tube is designed. Based on one-dimensional member model, the relationship between stress and displacement of boiler tube under prestressing force of anti-deformation rod is analyzed, and the theoretical results are compared with the numerical simulation results. The experimental results show that the pipe cladding platform has reasonable design, stable parameters, accurate positioning of boiler tubes, flexible disassembly, and the continuous cladding of 6m long boiler tubes can be realized. The characteristics of Cr3C2-NiCr cladding coating prepared by different process parameters were studied by using the laser cladding system designed by ourselves. The results show that the thickness of the cladding layer can reach lmm under the optimum parameters and the cladding layer is compact and metallurgical combined with the substrate material. The hardness analysis of the cladding layer for the sample of wear-resistant boiler tube shows that the microhardness is in the range of 1000-1150HV within 700 渭 m from the surface. The XRD analysis of the cladding shows that the main phase of the cladding is Cr3C2Cr7C3NiCr.
【学位授予单位】：华北电力大学(北京)
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM621.2;TN249

【参考文献】