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一般采用湿吹砂工艺清理及精整金属零件,而罗尔斯·罗易斯公司发现了其特殊用途,即:能清除RB211高压涡轮盘的压力裂纹。 In901合金是一种沉淀硬化型的镍—铁—铬—钼超级合金,能承受涡轮盘的各种苛刻条件,但对加工硬化极为敏感。为此,使用单点式硬质合金刀具,在规定的速率下进行最终加工,但往往还是在锻盘表面形成了构成疲劳源的应力裂纹。 大量试验证实,将盘的表面去,掉0.13mm就能消除应力裂纹,保证盘的使用寿命。表面层不能用机加方法去掉,因为这样会使加工硬化重现。酸蚀方法也不可取,因为能使裂纹向内部发展而使缺陷更严重。电化学方法并不实际。抛光、磨削及乾吹砂均能造成加工硬化。试验证实,只有湿吹砂工艺才能达到满意的结果。
The wet-grit process is generally used to clean and finish the metal parts, and Rawls-Royce has discovered its special use: to remove pressure cracks in the RB211 high-pressure turbine disk. In901 alloy is a precipitation hardened nickel-iron-chromium-molybdenum superalloy that withstands the rigors of turbine disks but is extremely susceptible to work hardening. To this end, the use of single-point carbide cutting tools, at the required rate of the final processing, but often formed on the surface of the forging fatigue stress cracks. A large number of tests confirmed that the disc surface, away 0.13mm can eliminate stress cracks, to ensure the service life of the disc. Surface layer can not be mechanically removed, because it will make work hardening reproduce. Erosion methods are also undesirable because of the internal crack growth that can make the defect worse. Electrochemical methods are not practical. Polishing, grinding and dry sand can cause work hardening. The test confirmed that only wet-blowing sand process to achieve satisfactory results.