芯管间隙对JAC590Y高强钢矩形管绕弯成形质量的影响

为了判断JAC590Y高强钢矩形管180°绕弯时芯棒与管坯之间的间隙大小对弯管成形质量的影响,基于Dynaform软件对4种芯管间隙下JAC590Y高强钢薄壁矩形管的绕弯成形分别进行了模拟,得出了不同芯管间隙值下弯管的主要畸变参数。结果表明:在芯管间隙处于一定范围内时,弯管的宽度扩展率受芯管间隙值的影响很小,而中面高度缩减率会随着芯管间隙的增大而变大;弯管上最大的壁厚减薄率出现于紧邻距芯棒最远芯头的横截面上顶板与两侧板的交角处,选取较大的芯管间隙有助于降低弯管的最大壁厚减薄率;JAC590Y高强钢薄壁矩形管180°绕弯成形时芯管间隙率的合理范围为0. 01~0. 025。

Influences of clearance between mandrel and tube on forming quality for JAC590Y high strength steel rectangular tube in rotary-draw bending

In order to judge the influences of the clearance between mandrel and tube on forming quality for JAC590 Y high strength steel rectangular tube in 180° rotary-draw bending,the rotary-draw bending processes of JAC590 Y high strength steel thin-walled rectangular tubes under four clearances between mandrel and tube were simulated respectively by software Dynaform,and the major distortion parameters of bent tubes were obtained under different clearances between mandrel and tube. The results show that when the clearance between mandrel and tube is in a certain range,the width extension of bent tube is little influenced by the clearance between mandrel and tube,and its mid-plane height reduction rate increases with the increasing of clearance between mandrel and tube. Furthermore,the maximum wall-thickness thinning rate of bent tube occurs at the corners between roof plate and two side plates in the cross-section close to the core farthest from the mandrel,and choosing larger clearance helps to reduce the maximum wall-thickness thinning rate of bent tube. Thus,in 180° rotary-draw bending of JAC590 Y high strength steel thin-walled rectangular tube,the reasonable range of the clearance rate between mandrel and tube is 0. 01-0. 025.