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本文主要综述国内外涡轮叶片加工工艺方法的现状与存在的问题,并对应用CNC砂带磨削技术加工涡轮叶片型面进行了展望。涡轮叶片通常由难加工材料制成,如:1Cr13,2Cr13,20CrM_o等。叶片材料又必须具备一定的特性,要有足够的机械性能,高的化学稳定性、耐气蚀性和导热性,低的热膨胀系数,并具有减振性好、工艺性好等特性。叶片的形状比较复杂,加工比较困难,加工工艺方法也经历了一个发展过程:无切削加工(锻造、铸造、辊辗);特种加工(电解、电火花);到有切削加工仿形、车削、刨削、铣削、磨削加工。目前叶片加工方式基本上还是采用仿形铣削、仿形磨削和砂带抛光。目前,国内生产叶片的工艺过程大致是:1)精铸或精锻毛坯;2)手工砂轮打磨;3)用模板测量规定截面;4)手工砂布机抛光。加工叶片中,第二、三道工序反复交替进行,直到用模板测量时透光达到图纸要求。叶片加工精度和表面质量很低,不利于生产效率和经济效益的提高,工人劳动环境和条件极差,严重损害工人身体健康和劳动积极性提高,这种生产状况极需改变。通过分析研究国内外有关叶片加工方面的可查文献及对叶片加工工艺方法的比较,可以看出唯有采用CNC砂带磨削技术加工叶片型面能很好地满足要求,该技术将是今后发展的一个主要方向。
This article mainly summarizes the current situation and existing problems of the turbine blade processing technology at home and abroad, and prospects the machining of the turbine blade surface by the CNC belt grinding technology. Turbine blades are usually made of difficult-to-machine materials, such as: 1Cr13, 2Cr13, 20CrM_o and so on. Leaf material and must have certain characteristics, to have sufficient mechanical properties, high chemical stability, resistance to cavitation and thermal conductivity, low thermal expansion coefficient, and has good damping properties, good process and other characteristics. Blade shape is more complex, processing more difficult, the processing technology has also undergone a development process: no cutting (forging, casting, roller); special processing (electrolysis, EDM); to a cutting profiling, turning, Planing, milling, grinding. At present, blade processing is basically still using profiling, profile grinding and belt polishing. At present, the process of domestic production blade is roughly: 1) casting or precision forging rough; 2) manual grinding wheel; 3) with the template to measure the required cross-section; 4) manual abrasive polishing machine. Processing leaves, the second and third procedures repeated alternately until the time of the template to measure the light transmission requirements. The processing precision and the surface quality of the leaves are very low, which is not conducive to the improvement of production efficiency and economic benefits. The working environment and conditions of workers are extremely poor, which seriously damage the health of workers and the enthusiasm of labor. Through the analysis of the domestic and foreign literature on leaf processing and comparison of leaf processing methods, it can be seen that only the use of CNC belt grinding blade technology to meet the requirements of the surface, the technology will be the future One of the main directions of development.