摘要
针对薄壁管管口内卷变形主要存在的原坯料端口开裂及原坯料端口切向失稳两种失效形式,提出以原坯料端口切向总应变(绝对值)不超过材料许用伸长率作为原坯料端口开裂的判据,其值与管外径D、管壁厚t和内卷半径R这3个几何参数有关。以D=Φ31.8 mm的304不锈钢薄壁管坯料为研究对象,仅设外支撑,施加轴向压力(简称轴压)迫使管口内卷,借助Deform-3D软件进行的数值模拟试验结果为:t=0.7 mm,1.50 mm≤R<2.00 mm时,内卷效果良好。实际试验结果为:R=1.50 mm,t=0.4~0.7mm时均能顺利内卷;R=2.25 mm,t为0.7和0.6 mm时,变形初期与数值模拟结果基本吻合,变形后期,原坯料端口多处严重开裂,t=0.5 mm时,出现原坯料端口切向失稳及管体失稳。研究表明,根据判据推算出的最大内卷半径R_(max)值可避免原坯料端口开裂,要避免原坯料端口切向失稳及管体失稳,也可以R_(max)值作参考。
Aiming at the two failure modes of nozzle inner roll deformation of the thin-walled tube,which are the cracking of raw billet port and the tangential instability of raw billet port.It was proposed that taking the total tangential strain(absolute value)of raw billet port does not exceed the allowable elongation of the material as the criterion for cracking of the raw billet port,which is related to the three geometric parameters of the outer diameter of tube D,the wall thickness of tube t and the inner radius R.Taking the thin-walled 304 stainless steel tube billet with D=Φ31.8 mm as the research object,with only external support,and axial pressure(referred to as axial pressure)was applied to force the nozzle to inner roll.The results of numerical simulation experiment with Deform-3D software show that when t=0.7 mm,1.50 mm≤R<2.00 mm,the inner roll effect is good.The actual experiment results show that when R=1.50 mm,t=0.4-0.7 mm,the inner roll can be achieved smoothly;when R=2.25 mm,t is 0.7 and 0.6 mm,the initial deformation is basically consistent with the numerical simulation results,and during the later deformation,the raw billet port is severely cracked in many parts,when t=0.5 mm,the tangential instability of raw billet port and the instability of tube body occur.The research shows that the maximum inner roll radius R max value calculated according to the criterion can avoid the cracking of raw billet port,and to avoid the tangential instability of raw billet port and the instability of tube body,the R max value can also be used as a reference.
作者
毛秋阳
张如华
虞班龙
欧阳经政
胡跃明
王华
黄青华
MAO Qiu-yang;ZHANG Ru-hua;YU Ban-long;OUYANG Jing-zheng;HU Yue-ming;WANG Hua;HUANG Qing-hua(School of Advanced Manufacturing,Nanchang University,Nanchang 330031,China;China Institute of Atomic Energy,Beijing 102413,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2023年第8期76-82,共7页
Journal of Plasticity Engineering
基金
中国原子能科学研究院委托项目。
关键词
管口内卷
开裂
失稳
数值模拟
实际试验
nozzle inner roll
cracking
instability
numerical simulation
actual experiment
