工艺参数对自由推压缩径管坯残余应力的影响  

Influence of process parameters on residual stress of tube blank in free pushing diameter-reducing

作　　者：刘超 吴娜[3] 杨志安 张士强[3] Liu Chao;Wu Na;Yang Zhian;Zhang Shiqiang(Department of Transportation and Vehicle Engineering,Tangshan University,Tangshan 063000,China;Key Laboratory of Intelligent Equipment Digital Design and Process Simulation of Hebei Province,Tangshan University,Tangshan 063000,China;College of Intelligent Manufacturing and Intelligent Transportation,Suzhou City University,Suzhou 215104,China;Tangshan Yate Special Vehicle Co.,Ltd.,Tangshan 063000,China)

机构地区：[1]唐山学院交通与车辆工程系,河北唐山063000 [2]唐山学院河北省智能装备数字化设计及过程仿真重点实验室,河北唐山063000 [3]苏州城市学院智能制造与智慧交通学院,江苏苏州215104 [4]唐山亚特专用汽车有限公司,河北唐山063000

出　　处：《锻压技术》2023年第4期95-102,共8页Forging & Stamping Technology

基　　金：唐山市科技计划项目(21130206D);河北省特种运载装备重点实验室开放基金课题;市级应用基础研究和人才培训专项(22130211G)。

摘　　要：针对自由推压缩径管坯弯曲疲劳寿命降低以及缩径时出现端部轴向开裂的问题,通过分析自由推压缩径的变形过程,揭示出缩径后已变形区内、外表面层存在较大的残余应力。使用有限元软件ABAQUS模拟了管坯的3道次自由推压缩径过程,给出已变形区内轴向、周向及径向残余应力沿长度方向、壁厚方向的分布规律,并分析了摩擦因数、缩径凹模出口圆角半径、缩径次数以及管坯的初始壁厚对缩径后残余应力的影响。对管坯进行了3道次缩径试验,实测了几何参量的变化,实测结果与有限元模拟值吻合,试验中发现第3次缩径时管坯出现了轴向开裂现象,证明了管坯内的周向残余拉应力值大于材料的强度极限。For the problems of reduced bending fatigue life of free pushing diameter-reducing for tube blanks and axial cracking at the end when the diameter was reduced,the deformation process of the free pushing diameter-reducing was analyzed,and it was revealed that there was a large residual stress in the inner and outer surface layers of the deformed area after the diameter was reduced.Therefore,the three-pass free pushing diameter-reducing process of tube blank was simulated by finite element software ABAQUS,and the distribution laws of the residual stress for the axial,circumferential and radial directions in the deformed area along the length direction and the wall thickness direction were obtained.Furthermore,the influences of friction coefficient,outlet radius of diameter-reducing die,diameter-reducing times and initial wall thickness of tube blank on the residual stress after diameter-reducing were analyzed.Finally,three-pass diameter-reducing tests were carried out on the tube blank,and the geometric parameter changes were measured,and the measured results were in good agreement with the finite element simulation values.It is found that the axial cracking occurs in the third diameter-reducing,which proves that the circumferential residual tensile stress is greater than the strength limit of material.

关 键 词：自由推压缩径 残余应力 轴向开裂 摩擦因数 变形不均匀 

分 类 号：TG316[金属学及工艺—金属压力加工]