护环液压缩径工艺数值模拟与试验研究  

Numerical simulation and experimental research on hydraulic necking technology for retaining ring

作　　者：李飞[1] 李鹏 何文武[1] 陈慧琴[1] Li Fei;Li Peng;He Wenwu;Chen Huiqin(School of Materials Science and Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,China)

机构地区：[1]太原科技大学材料科学与工程学院,山西太原030024

出　　处：《锻压技术》2020年第7期95-102,共8页Forging & Stamping Technology

基　　金：国家自然科学基金资助项目(51575372);山西省科技攻关计划(工业)项目(201603D121006-2);山西省重点学科建设经费资助。

摘　　要：采用有限元模拟与试验方法,分析了300 MW Mn18Cr18N钢护环液压缩径时的受力状态和变形规律。研究表明,液压缩径过程中,环坯内壁首先进入塑性变形状态,随着外压的逐渐升高,逐步向外壁扩展。变形过程中,环坯内壁、中壁和外壁变形相互协调。环坯内壁的等效应变和等效应力均始终大于外壁。模具锥角是影响环坯缩径形状的重要因素。由于模具锥角的改变,使得环坯端部受到的径向压力分量Fr和轴向压力分量Fz随之改变。当模具锥角较小时,径向压力分量Fr要明显大于轴向压力分量Fz,这导致采用小角度锥角的模具时,环坯缩径后往往呈现鼓肚形,当模具锥角较大时,轴向压力分量Fz将大于径向压力分量Fr,因此,采用大角度锥角的模具时,环坯缩径后呈现喇叭口形。通过数值模拟和试验验证的手段得出,当模具锥角在50°左右时,环坯可以获得较好的液压缩径效果。The stress states and deformation laws of 300 MW Mn18Cr18N steel retaining ring during hydraulic necking were analyzed by finite element simulation and experiment method.The result shows that the inner wall of ring blank enters plastic deformation state first,and then expands to the outer wall gradually with increasing of external pressure.During the deformation process,the deformations of ring blank’s inner,middle and outer walls are coordinated.Both the equivalent strain and equivalent stress of inner wall for ring blank are always larger than those of outer wall.The cone angle of die is an important factor that affects the shape of ring blank during necking.Due to the change of cone angles for die,the radial pressure component Frand the axial pressure component Fzon the end of ring blank are changed accordingly.When the cone angle of die is small,the radial pressure component Fris obviously larger than the axial pressure component Fz.It leads to the bulging shape of ring blank after necking when the die with small cone angle is used.When the cone angle of die is large,the axial pressure component Fzwill be larger than the radial pressure component Fr.Therefore,when the die with large cone angle is used,the ring blank presents a trumpet shape after necking.By means of numerical simulation and experimental verification,it concludes that when the cone angle of die is about 50°,the ring blank can obtain better hydraulic necking effect.

关 键 词：Mn18Cr18N钢 护环 液压缩径 塑性变形 液体外压 模具锥角 

分 类 号：TB24[一般工业技术—工程设计测绘]