异形孔筒形锻件成形表面不平整度分析及验证  

Analysis and verification of forming surface unevenness of cylindrical forgings with special-shaped holes

作　　者：张庆玲[1] 刘新宇 金淼[1] ZHANG Qing-ling;LIU Xin-yu;JIN Miao(College of Mechanical Engineering,Yanshan University,Qinhuangdao 066004,China;Qilu Zhongke Institute of Optics Physics and Engineering Technology,Jinan 250000,China)

机构地区：[1]燕山大学机械工程学院,河北秦皇岛066004 [2]齐鲁中科光物理与工程技术研究院,山东济南250000

出　　处：《塑性工程学报》2024年第10期27-34,共8页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(52075474);中央引导地方科技发展资金资助项目(246Z1016G)。

摘　　要：针对异形孔筒形锻件成形过程中金属在反向流动中流速不均匀导致的锻件上表面产生不平整缺陷的问题,以椭圆孔筒形锻件为例,采用数值模拟与试验相结合的手段,探究了锻件上表面不平整现象的成因。分别从一维、二维、三维建立了异形孔筒形锻件上表面不平整度的评判准则,进一步揭示了成形工艺参数对异形孔筒形锻件上表面不平整度的影响规律。结果表明:异形孔筒形锻件上表面不平整度随模具预热温度的升高而降低,随坯料始锻温度的升高而增大,始锻温度比模具预热温度对上表面不平整度的影响更大;提高成形速度可以降低金属的流动阻力,减小坯料的温降,改善坯料变形和温度分布的均匀性,从而降低异形孔筒形锻件上表面的不平整度;异形孔筒形锻件上表面不平整度还受椭圆孔短长轴比值的影响,凸模横截面积恒定时,随短长轴比值增大,不平整度评价指标均呈下降趋势;凸模短轴值恒定,长轴值超过锻件外径的2/3时,随短长轴比值增大,不平整度评价指标呈现先增大后减小的趋势,长轴值小于锻件外径的2/3时,不平整度评价指标随短长轴比值增大呈现下降趋势。Aiming at the problem of uneven defects on the upper surface of the forgings by uneven flow rate of the metal in the reverse flow during forming process for cylindrical forgings with special-shaped holes,taking the cylindrical forgings with elliptical holes as an example,the causes of upper surface unevenness phenomenon for forgings were investigated by means of numerical simulation and experiment.The evaluation criteria of upper surface unevenness of cylindrical forgings with special-shaped holes were established from the dimensions of one,two and three dimensions,respectively,and the effect laws of forming process parameters on upper surface unevenness of cylindrical forgings with special-sheaped holes were further revealed.The results show that the upper surface unevenness of cylindrical forgings with special-shaped holes decreases with the increase of mold preheating temperature,and increases with the increase of blank initial forging temperature.The initial forging temperature has a greater effect on the upper surface unevenness than the mold preheating temperature.Increasing the forming speed can reduce the metal flow resistance,reduce the temperature drop of the blank,and improve the uniformity of the blank deformation and temperature distribution,and thus reduce the unevenness of the upper surface of the cylinder forging with special-shaped holes.The upper surface unevenness evaluation of cylindrical forgings with special-shaped holes is also affected by the short-long axis ratio of elliptical holes.When the cross sectional area of punch is constant,the evaluation indexes of unerenness decrease with the increase of the short-long axis ratio.When the short axis value of the punch is constant and the long axis value is more than 2/3 of the outer diameter of the forging,the unevenness evaluation index increases first and then decreases with the increase of short-long axis ratio.When the long axis value is less than 2/3 of the outer diameter of the forging,the unevenness evaluation index dcreases with the inc

关 键 词：异形孔 挤压成形 仿真 表面不平整度 工艺参数 

分 类 号：TG316[金属学及工艺—金属压力加工]