弧型模和锥型模空拔钢管成型机理的研究

Forming mechanism of empty-sunken steel tube formed with arc die and conical die

采用非线性有限元法对弧型模和锥型模的空拔钢管成型过程进行了数值模拟,得到了钢管在整个成型过程包括入模、稳定拔制和钢管脱模以后各个阶段的位移场和应力应变场。根据数值计算结果绘制了钢管的轴向、环向及径向应力分布,根据应力分布绘制了钢管在成型前区、减径区、定径区及成型后区的三向应力状态,最后根据应力分布特点解释了弧型模和锥型模如何影响成品钢管直径和壁厚精度的机理。数值计算结果表明:采用弧型模成型的钢管直径精度高,采用锥型模成型的钢管壁厚精度高,而采用介于弧型模和锥型模之间的新型模具可以兼顾直径和壁厚的精度。研究成果对于空拔钢管模具设计和成型工艺设计有参考价值。

The numerical simulation of the forming process of empty-sunken steel tube formed with arc die and conical die was conducted by nonlinear finite element method. The distributions of the displacement, stress and strain of the whole forming process of the steel tube were obtained. According to the numerical calculation results, the distributions of the axial stress, circle stress and radial stress and three-dimensional stress states of the steel tube at different areas were drawn. The mechanism that the arc die and conical die influence the preci- sion of both the diameter and wall thickness of the tube were explained according to the stress distributions. The numerical calc, ulation results show that the high precision of the diameter can be obtained by arc die, the high precision of the wall thickness can be obtained by conical die, and the high precision of both the diameter and the wall thickness can be obtained by an innovative die. The results of the research can be applied to the design of both the die and the forming process.