长锥管增量成形扩口工艺研究

Research on incremental flaring forming process of long conical pipe

由于传统扩口成形在加工长锥管精密零件时存在局限性,将增量成形技术引入金属管管端成形,针对304不锈钢管扩口变形的成形特点提出了一种长锥管增量成形扩口工艺,设计了合理的试验工装。基于ABAQUS/Explicit建立了管端增量成形的仿真模型,通过数值模拟的方法对工艺参数进行了初选并预测了管端扩口成形缺陷,仿真结果表明,随着滚压头的进给,成形区底部材料发生失稳屈曲,因此,在长锥管扩口成形中存在成形极限,而影响成形极限的主要因素为摩擦和扩口高度,在此基础上提出了多道次成形改进方案。最后通过试验验证了改进后工艺的可行性和成形件的可靠性,极大地缩短了生产周期,并节约了成本。

Due to the limitation of traditional flaring forming in machining long conical pipe precision parts,the incremental forming technology was introduced into metal pipe end forming.According to the forming characteristics of 304 stainless steel pipe flaring deformation an incremental flaring forming process of long cone pipe was put forward,and the reasonable test tool was designed.The simulation model of pipe end incremental forming was established based on ABAQUS/Explicit.The process parameters were preliminarily selected by numerical simulation method and the flaring forming defects in pipe end were predicted.The simulation results show that instability and buckling occur at the bottom of the material in the forming zone with the feed of roller head.Therefore,forming limit exists in the flaring forming of long conical pipe,and the main factors affecting the forming limit are friction and flaring height.On this basis,improved scheme of multi-pass forming was proposed.Finally,the feasibility of the improved process and the reliability of the formed parts were verified by test,which greatly shortens the production cycle and saves the cost.