微孔高温合金蜂窝半正六边形波纹结构制造工艺研究

发布时间：2018-03-24 12:34

本文选题：微孔蜂窝　切入点：有限元分析　出处：《哈尔滨工业大学》2015年硕士论文

【摘要】：汽轮机是将蒸汽的能量转换为机械功的旋转式动力机械,在航空、船舶及核、火电等领域有广泛应用。汽轮机的密封性与高温蒸汽的利用率及生产安全紧密相关,传统的梳齿密封方式因自身缺陷已经无法满足现代汽轮机的工作要求,近年来逐渐被性能更优异的蜂窝密封所取代。但国内制造的密封蜂窝质量不佳,产品供应和技术支持受制于外国始终制约着我国轮机产业。本文以镍基高温合金GH536为微孔金属蜂窝基体材料,系统研究密封用微孔蜂窝半正六边形波纹结构的成形工艺和蜂窝带组装方法。在明确基体材料特性、蜂窝应用场合和质量要求的基础上,根据金属塑性成形原理和成形过程力学分析得到仿真计算过程中各关键参数的选取依据。运用有限元分析和实际验证相结合的方法,通过仿真分析得到滚压成形方法关键部件成形辊的齿顶棱边倒角和齿数等优化几何参数,以此为依据设计出相应的成形装置。通过滚压成形验证,对所研制的成形装置改进优化,结果表明,滚压法成形箔片过程中箔片两侧面受力程度不同,成形出的蜂窝半正六边形波纹结构整体局部弯曲,单齿侧面尺寸不对称,难以组装出合格蜂窝。在分析滚压成形方式所存在不足的基础上,针对性地研究了半正六边形波纹结构的冲压成形方法,通过有限元数值模拟仿真分析得到凸凹模的优化结构形式和齿廓棱边倒角、邻边夹角等设计参数,以此为依据设计冲压模,并进行冲压成形验证,然后再根据验证结果对模具进行优化,结果表明,冲压法制造的蜂窝半正六边形波纹结构整体平直,单齿对称,邻边夹角接近理想值,能满足设计要求。以验证过程和结果为依据,对基于滚压法和冲压法的微孔金属蜂窝成形方式进行了综合比较分析,指出了各自的优缺点及对产品质量的影响,并在此基础上选择冲压成形件对微孔金属蜂窝成形工艺进行了优化设计。本文最后还对基于激光焊接法的微孔金属蜂窝带的组装过程进行了研究,通过焊接组装实验验证了半正六边形波纹结构的成形质量要求,制造出了长度为20 mm的蜂窝带样件。
[Abstract]:Steam turbine is a rotary power machine which converts steam energy into mechanical power. It is widely used in aviation, ship and nuclear, thermal power, etc. The seal of steam turbine is closely related to the utilization ratio of high temperature steam and the safety of production. The traditional comb seal has been unable to meet the requirements of modern steam turbine due to its own defects. In recent years, it has been gradually replaced by the honeycomb seal with better performance. However, the quality of the seal honeycomb made in China is not good. The supply and technical support of products are restricted by foreign countries, which have always restricted the marine engineering industry in China. In this paper, nickel-based superalloy GH536 is used as microporous metal honeycomb matrix material. The forming process and the assembly method of honeycomb semi-hexagonal corrugated structure for sealing were studied systematically. On the basis of defining the properties of matrix material, the application situation and quality requirement of honeycomb, According to the principle of metal plastic forming and the mechanical analysis of forming process, the basis of selecting the key parameters in the process of simulation calculation is obtained, and the method of combining finite element analysis with practical verification is used. Through the simulation analysis, the optimized geometric parameters such as the top edge chamfering angle and the tooth number of the forming roll are obtained, and the corresponding forming device is designed. The improvement and optimization of the developed forming device show that the two sides of the foil are subjected to different forces in the process of rolling forming foil, and the beehive semi-hexagonal corrugated structure is partially bent and the dimension of the single tooth side is asymmetrical. It is difficult to assemble qualified honeycomb. On the basis of analyzing the deficiency of rolling forming method, the stamping forming method of semi-hexagonal corrugated structure is studied. Through the finite element numerical simulation analysis, the optimized structure form of the convex and concave die and the design parameters such as the chamfering angle of the tooth profile edge and the angle between the adjacent edges are obtained. The stamping die is designed on the basis of which the stamping die is designed, and the stamping forming is verified. Then the die is optimized according to the verification results. The results show that the beehive semi-hexagonal corrugated structure made by the punching method is whole straight, symmetrical with one tooth, and the angle of adjacent edge is close to the ideal value. According to the verification process and results, the forming methods of microporous metal honeycomb based on rolling and stamping methods are compared and analyzed, and their advantages and disadvantages are pointed out as well as their effects on product quality. On the basis of this, the forming process of microporous metal honeycomb is optimized and the assembly process of microporous metal honeycomb strip based on laser welding is studied. The forming quality requirement of semi-hexagonal corrugated structure was verified by welding assembly experiment, and a sample of honeycomb strip with length of 20 mm was fabricated.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TK266

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