摘要: |
针对重型运载火箭增压输送系统管路的应用需求,开展了大直径不锈钢波纹管的成型工艺研究,突破了通径Φ470mm且单层壁厚为1.3mm的双层大直径不锈钢波纹管的精密成型技术,成型精度及性能满足重型运载火箭的服役工况。大直径不锈钢波纹管在2.25MPa和1.5MPa条件下分别开展液压强度试验和气密试验并保压5min,均未出现波纹管的失稳以及泄漏情况;通过液氮浸泡进行低温冷冲击试验,波纹管未出现开裂和变形等异常现象;通过压缩10mm的方式测试波纹管的机械刚度,刚度值达到630N/mm;内部充液压1.5MPa并进行拉伸60mm的位移疲劳试验,经300次循环后未出现失稳,且气密检查未出现泄漏,极限拉伸至120mm时才开始出现端波的平面失稳。 |
关键词: 大直径波纹管;成型精度;位移疲劳试验;重型运载火箭 |
基金项目: |
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Research on Forming Processes and Mechanical Performance of Large-diameter Stainless Steel Bellows |
Li Jinquan Tian Xin Wu Yichuan Wang Shuo Wang Wei
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Capital Aerospace Machinery Co., Ltd., Beijing 100076
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Abstract: |
To meet the application requirement of pipes in the pressurization and delivering system of the heavy-lift launch vehicle, the forming processes of large-diameter stainless steel bellows were conducted in this paper. The precise forming technology of double-layer large-diameter stainless steel bellows with an inner diameter Φ470mm and a single-layer thickness 1.3mm was broken through. Meanwhile, both the forming precision and its mechanical performance could meet the service conditions of the heavy-lift launch vehicle. As for the large-diameter stainless steel bellow, the hydraulic strength test of 2.25MPa and the gas leakage test of 1.5MPa were carried out respectively with a pressure-holding time 5min, and there was no instability or leakage phenomenon. The cold-impingement testing at cryogenic temperature was also carried out through the liquid nitrogen immersion, there was no abnormal phenomena such as cracking and deformation found on the bellow. The mechanical stiffness of the bellow was also tested through a compression process of 10mm, the mechanical stiffness value reached 630N/mm. The displacement fatigue test was carried out under the condition of an inner hydraulic pressure 1.5MPa and a tensile displacement 60mm. There was no instability after a test of 300 cycles and also no leakage during the gas leakage test, and the plane instability began to appear on the end wave when the bellow was ultimately stretched to an elongation of 120mm. |
Key words: large-diameter bellows;forming precision;displacement fatigue test;heavy-lift launch vehicle |