Research on Metal Bellows of Special Purpose
|School||Shenyang University of Technology|
|Keywords||Metal bellows design forming technology|
To improve the launching ability of delivery rocket, keep and improve the state of super aerospace country of China, the research of new model Hydrogen-Oxygen Rocket Engine is started in our country. Many high performance metal bellows are applied in the dynamical system of the rocket engine. Comparing to the previous model, the technical performance of new model engine improves greatly, the requirement for metal bellows improves correspondingly. Either in design or manufacture, the improvement is great, Max. Working pressure is 24.0 MPa, Max. working displacement is 27mm, Max inner diameter is φ200mm, lowest work temperature is -253℃, Many new material, structure and technology are adopted.Special metal bellows in rocket engine system is not only a control part, but also as a move part of seal of low temperature, it is a key part, with its key function could not be substituted by other parts.Metal bellows is a thin wall thickness tube part, with landscape orientation ripple, Itpossesses the function of elasticity, and various capabilities as resistance of pressure, seal, corrosion resistance, thermal resistance etc. The research of special metal bellows is a system engineering belonging to technique category of especially thin thickness pipe machining further which requires high precision of dimension, and reaches various high technique performance and reliability that required. The research covers design of bellows, precision plasticity machining of especially thin thickness pipe, brightness heat treatment, precision welding, precision cutting and testing etc. various technology and technique. The performance of metal bellows is mainly decided by structure, geometry dimension, material and manufacture technology.During the research of the project, we refered to the condition and development of the technique inside and outside China, and lucubrated the design, manufacture technology and test. The most advanced EJMA design formula of world is adopted to design the bellows, and consummated by test, new structure "S-wave", new material "GH4169", little pitch, and shallow ripple wre adopted to improve the pressure endurance of bellows, metal plasticitytheory is adopted to analyze the forming process of bellows, design clamps and forming technology, special forming medium is adopted to ensure the layer quality of multi-ply bellows, plasticity forming theory, chemical principle and new material are adopted to capture the key technology of "S-wave" forming and model dissolving, and with advanced vacuum brightness heat treatment to improve the performance of the bellows.The special metal bellows researched, research the technical requirements completely, fulfilled the requirements on rocket engine’s research. The whole technical level of the project has reached the international advanced level.