不锈钢凸缘管材充液成形模拟分析

Simulation Analysis of Hydroforming Process of Stainless Steel Flange Pipe

针对一种航空用凸缘卡箍零件,对不锈钢管材进行充液成形工艺研究。通过DYNAFORM有限元分析软件建立了1Cr18Ni9不锈钢管材充液成形模型,探究了单工序高压成形和双工序低压预成形及高压整形工艺对零件减薄率和贴模度情况的影响。研究结果表明:管材成形工序影响材料流动,对凸缘零件最终成形结果存在很大影响。单工序高压成形时接触摩擦力过大,不利于材料的流动,造成零件减薄率过大并开裂。双工序的低压预成形阶段可以促进材料流动,胀形压力为20 MPa时材料流动不足,零件贴模度较差。胀形压力高于30 MPa时,凸缘变形量过大导致零件翘起。当胀形压力为25 MPa、合模距离为10 mm、整形压力为150 MPa时,零件减薄率适中,贴模度良好,可以成功加工出凸缘卡箍零件。

Aiming at a kind of aviation flange clamp part,the hydroforming process of stainless steel pipe was studied.The finite element model of 1Cr18Ni9 steel pipe hydroforming was established by DYNAFORM,and the influence of single process of high pressure hydroforming and double process of low pressure preforming followed by high pressure shaping on the thinning rate and stick modulus of part was investigated.The result showed that the pipe hydroforming process affected the material flow and had great influence on the forming result of flange parts.The contact friction was too large during the high-pressure expansion of the single process,which can not make full use of the flow property of the material,resulting in excessive thinning rate and cracking of the parts.The low pressure preforming stage in the double process can promoted the flow of materials,and with an expansion pressure of 20 MPa there was insufficient material flow and poor stick modulus.When the expansion pressure was higher than 30 MPa,the deformation of the flange was too large,resulting in warpage of the part.When the expansion pressure was 25 MPa,the initial closing distance was 10 mm,and the shaping pressure was 150 MPa,the parts’thinning rate was moderated and the stick modulus was good,and the flange parts can be sucessfully processed.