摘要
厚壁深孔筒形件常见成形工序为压型、冲盂和拔伸,拔伸时坯料变形剧烈、成形稳定性差,容易出现顺挤、偏心、表面拉伤等缺陷,故拔伸是筒形件成形的关键工序。基于理论分析、数值模拟和工艺试验,对筒形件单模圈和两模圈拔伸工艺和顺挤缺陷进行了研究。研究结果表明:拔伸时坯料所受轴向拉应力在模圈出口处Ⅱ-Ⅱ截面达到最大;拔伸模圈入模角为15°时坯料所受轴向拉应力最小,对成形最有利;模圈和坯料之间润滑状态越好,凸模和坯料之间润滑状态越差,坯料顺挤现象越严重;采用两模圈拔伸,模圈工作带直径分别为Φ47和Φ44 mm,模圈间距为105 mm,可获得平均壁厚差为0.82 mm的成形件。
Upsetting, cupping and drawing are the most common processes for thick wall and deep hole cylindrical cup, and the forming of billet is very violent and unstable during drawing. The forming defects easily happen, including downflow, decentration, surface scratch phenomenon and etc. , so drawing is the key process to hot stamping of thick wall and deep hole cylindrical cup. Drawing process with one bottom die and two bottom dies were researched based on theoretical analysis, numerical simulation and process experiment. The results show that the tensile stress value of billet is the maximum in the cross-sectional ll - II of bottom die. When the die-entrance taper of die was 15°, the axial tensile stress value is the mininum, which is the most benifit for forming. The better lubrication condition between bot- tom die and billet, the worse one between top die and billet, and the more serious downflow phenomenon. When two-pass drawing was used, the diameters of bearing land of bottom die respectively are Ф47 and Ф44 mm, the distance between two dies is 105 mm, and formed parts whose average wall thickness difference is 0. 82 mm are obtained.
出处
《锻压技术》
CAS
CSCD
北大核心
2014年第6期24-28,共5页
Forging & Stamping Technology
基金
国家科技重大专项资助项目(2011ZX04001-051-03)
关键词
筒形件
拔伸工艺
模圈入模角
顺挤缺陷
数值模拟
cylindrical cup
drawing process
die-entrance taper
downflow default
numerical simulation
