超薄壁大径厚比筒体旋压鼓形失稳机理与规律  

Mechanism and behavior of drum style instability during flow forming of extra-thin-walled tube with high ratio of diameter/thickness

作　　者：李新和[1] 何霞辉[1] 邓锐[1] 刘燕平[1] 秦清源[1] 

机构地区：[1]中南大学高性能复杂制造国家重点实验室,长沙410083

出　　处：《塑性工程学报》2011年第5期99-104,共6页Journal of Plasticity Engineering

基　　金：国家重点基础研究发展计划(973)资助项目(2009CB724300)

摘　　要：运用有限元软件MSC.Marc模拟超薄壁大径厚比筒体减薄旋压加载过程,研究载荷、工模配合间隙、工件直径及厚度对旋压鼓形失稳的影响规律。结果表明,载荷、配合间隙和工件直径越大、壁厚越小,越容易产生鼓形失稳缺陷。以哈氏合金C276为毛坯材料,进行直径为561.5mm、厚度为0.42mm筒体的减薄旋压实验,实验结果与仿真分析吻合;在深入分析超薄壁大径厚比筒体旋压的力流特性和约束特性,探讨旋压鼓形的形成机理的基础上,提出了间隙率和锁模环的概念及其对旋压过程的影响,并提出了鼓形失稳的调控措施,为超薄壁大径厚比回转件的整体减薄旋压成形提供理论指导和工艺借鉴。FEM software MSC.Marc was applied to simulate the backward flow forming of extra-thin-walled tube with high ratio of diameter-thickness.The influence of the load,the clearance,and the diameter and thickness of the workpiece to the drum style instability during flow forming were studied.The drum height increased with the increase of the load,clearance and diameter of the tube and the decrease of thickness.The blank material used was Hestelloy-C276.The flow formed tube was 561.5mm in diameter and 0.42mm in thickness.The experimental result was consistent with simulation result.The forming mechanism of drum style instability was discussed through analyzing the characteristics of force transmission and constraint during flow forming.The conceptions of the clamping loop and the rate of clearance were proposed.The regulation measures for the drum style instability suggested may provide theoretical guidance for the flow forming process.

关 键 词：减薄旋压 鼓形失稳 大径厚比 间隙率 锁模环 

分 类 号：TG306[金属学及工艺—金属压力加工]