| Precision forming technology is one of the most important aspects in advanced manufacturing technology, and it is the key technology to improve properties and qualities of produce. It not only can cut down the manufacturing period of product, reduce the cost and the reduce the weight of product, but also can acquire excellent structure of the forging, improve the final accuracy and roughness of the product, increase the security reliability and life span of productl. In addition, it can consumedly increase material utilization, economize on energy and material, improve produces condition and reduce every kind of contaminative source. So thermo-plastic precision forming technology has developed into one of the very important and promising new method for mechanical parts machining. In the process of every little or without cut scraps, the precondition to realizes precision forming is that the strict volume accuracy and the good surface quality. It is also the crucial reason that the thermo-plastic precision forming techniques, precision forging for example, can not be large-scaled developed, because the heating technology without or little oxidation can not pass the barrier. High effective heating technology without or little oxidation and prevention oxidation during thermo-plastic forming are key kit technology to realize precision forming.At present, quick heating or medium protected heating to reduce or prevent oxidation during heating are often used in the process of thermo-plastic forming such as forging. Gas protected medium is one of the most common used and the most effective method. There are three main kinds of way to use gas to protectbillet, according to the different preparation method of protected atmosphere, there are endothermic atmosphere, euthermic atmosphere and nitrogen-based atmosphere. In which the nitrogen-based atmosphere is used widily for its safe, economical and adaptive, especially in the area of heat treatment. Gas protect heating can reduce and prevent billet oxidation effectively in heating process, but it cannot avoid oxidation during the forming and cooling, which takes extremely disadvantage to precision forming.My tutor, Professor Song Yuquan, has devoted himself to metal hot plasticity precision forming for many years and obtained series of achievements. Now his some patents are being transformed and actualized. As to oxidation during thermo-plastic precision forming, my tutor firstly puts forward audacious assumption of building a machining workshop without oxidation by controlled atmosphere. That is to say, all the process from heating, forming, and cooling during thermo-plastic precision forming are done in a controllable and airtight room, which can effectively prevent or decrease oxidation and decarbonization by adjusting gas components in airtight room. Therefore, this paper is one part of the overall research continuously on local plastic precision forming of my tutor, which provides kit techniques for thermo-plastic precision forming without or little oxidation.The nitrogen-based atmosphere is a synthetic protection atmosphere that is made nitrogen as basic gas and added the just right amount of additive. Therefore, the source of nitrogen is precondition to nitrogen-based atmosphere. It is a basic technical and economy condition of preparation for nitrogen-based atmosphere that to select the best way to supply nitrogen and with high quality and low price. We choose the advanced membrane separation nitrogen producing device as our getting nitrogen equipment. Membrane separation technology is a new technology, which came forth in 1960s and matured till to1980s. It is deemed as the best advanced separation to get nitrogen because it has many merits such as simpleness in machine structure, low in energy consume, high reliability, long life span, and the easiness to be operated and controled as well. The membrane separation nitrogen producing device in the paper mainly includes two parts: gas source machine and mainframe. The gas source...
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