深孔枪钻加工过程中，被加工孔直径小、孔深长，切屑形貌是影响其加工质量 的一个重要因素，并且切屑的成形机理和与工艺参数之间的关系也一直是深孔加工研究 的难点。本研究以15-5PH 不锈钢为研究对象，通过对切屑的流动过程分析，研究枪钻 加工螺旋形切屑成形的过程和影响因素。借助扫描电镜检测切屑断面不同点的形貌，研究15-5PH 不锈钢枪钻加工切屑的断裂机理。通过改变切削速度、进给量和油压的试 验，分析了不同工艺参数下的切屑变形规律。借助 ANSYS-FLUENT 仿真软件，分析不 同油压枪钻前刀面刃口的流体压力和湍流动量，阐述了切屑变形与油压的影响关系。研 究发现15-5PH 不锈钢深孔枪钻加工切屑属于“准解理断裂”，切屑形貌与枪钻工艺参 数选择密切关联；本研究的结果对15-5PH 不锈钢深孔枪钻加工工艺参数和冷却液油压 的优化选择具有指导意义和参考价值。

Chip shape is an important factor affecting the processing quality of the deep hole gun drilling, because the hole is too small and deep. The relationship between chip forming mechanism and process parameters has long been a difficult problem in deep hole gun drilling research. Taking 15-5PH stainless steel as the research object, the research explored the process and influencing factors of spiral chip forming by analyzing the chip flow process. The fracture mechanism of 15-5PH stainless steel gun drilling chips was studied with scanning electron microscope. The chip deformation rule under different process parameters was studied through experiments with varied cutting speed, feed, and oil pressure. The relationship between chip deformation and oil pressure was clarified by analysing fluid pressure and turbulent momentum on the cutting edge of gun drilling under different oil pressure with ANSYS-FLUENT. The study shows that the fracture mechanism of chips processed by 15-5PH stainless steel gun drill belongs to “quasi-cleavage fracture” and the chip morphology is closely related to the technical parameters of the gun drill. The research results can provide guidance and references for the selection of processing parameters and coolant oil pressure of deep hole gun drilling of 15-5PH stainless steel.