强化感应加热辅助磨削Inconel718的 残余应力主动调控

镍基高温合金Inconel718具有良好的高温强度和高耐蚀性能,广泛应用于制造航空工业特别是燃气涡轮发动机的高温构件。然而最终的成形磨削工艺常常在零件表面形成较大的残余拉应力,这对其疲劳强度和寿命等服役性能极为不利。研究和开发了一种基于磨削区的热温度梯度调节原理的复合磨削工艺,以主动调节Inconel718零件表面残余应力分布。在磨削工艺中利用控制良好的感应加热装置将热源嵌入到工件亚表层,通过对所需的温度梯度分布的主动控制实现对残余应力的调节。结果表明,通过合理调节感应加热和磨削工艺参数,可以获得较小的表面残余拉应力甚至压应力分布。本研究能够减少当前生产中为获得表面残余压应力而额外采取的喷丸等后续工艺,实现磨削残余应力的在线主动控制,且该技术也可以扩展推广应用到其他材料以及其他加工工艺中,如切削、铣削等。

Nickel-based superalloy Inconel 718 possesses high strength and corrosion resistance, which is widely applied in aviation industry, especially the high temperature components of gas turbine engines. However, the final forming grinding process often forms a large residual tensile stress on the surface of the parts, which is detrimental to the fatigue strength and life of the parts. A combined grinding process based on the principle of the thermal gradient adjustment in grinding zone is studied, which could adjust the residual stress distribution on the surface of Inconel718 parts actively. In the combined grinding process, the heat source is embedded into the sub-surface of the workpiece by induction heating equipments well controlled, which can adjust the residual stress by the active control of the temperature gradient. The results show that the smaller surface residual tensile stress and even compressive stress distribution can be obtained by reasonably adjusting the parameters of the induction heating and grinding process. This study can reduce the extra shot peening process during the current production in order to obtain the compressive residual stress on the surface, and realize the on-line active control of the grinding residual stress. Furthermore, the combined grinding technology can be extended to the other materials and machining processes, such as cutting, milling, etc.