微小尺寸等壁厚不锈钢螺旋管充液压制成形方法研究

为了解决常规螺杆钻具寿命短与微小尺寸螺杆钻具等壁厚定子难加工的问题，本文采用充液压制成形工艺加工微小尺寸等壁厚螺旋管，基于304不锈钢拉伸实验，建立了充液压制成形等壁厚螺旋管有限元模型，用数值模拟方法研究管件外径、壁厚、液压力大小、液压力加载路径、压制速度、摩擦系数对螺旋管质量的影响。结果表明，管件外径为51.8 mm，壁厚为5.3 mm时，螺旋管质量较好，最大液压力为650 MPa，液压力加载路径为路径5，模具挤压速度为0.429 m/s，摩擦因数不超过0.125时，螺旋管加工质量较好，导程误差近似为0，壁厚误差小于8%，平均厚度为5 mm，螺旋管中部壁厚误差小于3%。研究结果可为生产实际中微小尺寸等壁厚不锈钢螺旋管的成形工艺提供参考。

Study on Hydraulic Pressure Forming of Stainless Steel Spiral Pipe with Small Size and Equal Wall Thickness

In order to solve the short life of the conventional screw drill and the difficulty of machining small-sized stator of the screw drill with equal wall thickness, this paper uses hydraulic pressure forming technology to manufacture the small-sized equal-wall spiral tubes. Based on the 304 stainless steel tensile experiment, a finite element model for spiral tube with equal wall thickness formed by hydraulic pressure was established. The numerical simulation method is used to study the influence of the pipe outer diameter, wall thickness, hydraulic pressure, hydraulic pressure loading path, pressing speed and friction coefficient on the quality of the spiral pipe. The results show that when the outer diameter of the pipe is 51.8 mm and the wall thickness is 5.3 mm, the quality of the spiral pipe is better, the maximum hydraulic pressure is 650 MPa, the hydraulic pressure loading path is path 5, and the extrusion speed of the die is 0.429 m/s. When the friction coefficient does not exceed 0.125, the spiral tube quality is better, the lead error is approximately 0, the wall thickness error is less than 8%, the average thickness is 5 mm, and the wall thickness error in the middle of the spiral tube is less than 3%. The result can provide the reference for forming the stainless steel spiral pipe with the small size and equal wall thickness.