成型参数对HFW焊管排辊成型质量的影响

HFW(high frequency welding)焊管的排辊成型过程主要受材料、成型设计、工艺设计方面因素的影响。实际生产中需要知道各影响因素对产品成型质量的影响,为生产工艺的制定提供理论上的参数定性、定量选择依据。基于508 mm直缝焊管的排辊成型过程,利用有限元分析软件ABAQUS仿真,将带钢的成型形状、边部纵向应变曲线、边部PEEQ(等效塑性应变)曲线作为评价指标,探讨了成型速度、摩擦状态对管坯成型效果的影响。结果表明,在正常取值下,速度和摩擦状态对成型形状无较大影响,速度对边部纵向应变以及边部PEEQ影响较大,摩擦因数对边部纵向应变影响较大,对边部PEEQ基本无影响。     

基于混合硬化模型的ERW焊管排辊成形数值模拟

针对ERW焊管排辊成形过程中带刚反复加载、卸载的复杂成形工艺特点,提出了考虑包辛格效应的混合硬化材料本构模型;通过ABAQUS用户材料子程序VUMAT的二次开发,对混合硬化材料的本构模型进行了有限元程序实现;基于混合硬化模型,对ERW焊管排辊成形过程进行了数值模拟,分析了成形过程中应力应变的变化规律,并对计算结果进行了对比。结果表明,混合硬化模型能够很好地体现ERW焊管排辊成形反复加载、卸载的成形工艺特点;不同的材料硬化模型对排辊成形过程中板料的应力应变产生较大影响。     

大直径ERW直缝焊管排辊成型的有限元模拟

采用大型非线性有限元软件Marc对ERW直缝焊管的排辊成型过程进行模拟．获得了成型管坯形状以及各机架截面处和沿板带纵向的等效应力与应变场分布;分析了排辊成型面与管坯的接触状态。为排辊成型焊管机组的孔型设计以及排辊调整提供了理论依据。     

螺旋焊管机组辊式预弯边装置的孔型设计——螺旋焊管成型用带钢纵向边缘预弯曲率的近似计算

在螺旋焊管生产过程中,带钢纵向边缘预弯对预防和控制焊管成型缝产生"桃形尖"缺欠非常重要。介绍了一种辊式预弯边装置的孔型设计方法,给出了带钢弯曲成型时的边部翘曲曲率的计算公式,建立了带钢边部在辊式预弯边装置中的预弯曲率(指中性层)1/ρ预的数学模型,为二辊式预弯边装置的预弯辊辊型设计和三辊式预弯边装置的预弯调整指明了方向,对改善螺旋焊管成型缝质量和实际生产都具有一定的指导意义。     

外卷边槽钢多道次辊弯成型数值模拟

利用有限元软件ABAQUS对外卷边槽钢的多道次辊弯成型过程进行了数值模拟。基于动力显示算法,采用引导板料入辊方式建立了外卷边槽钢多道次辊弯成型有限元模型。分析了成型过程中槽钢的金属变形状态与应力应变场的变化情况,并重点研究了外卷边槽钢边部纵向应变、内外弯角处厚度与横向应变在成型过程中的变化情况,为优化多道次辊弯成型工艺提供了理论依据。     

HFW焊管排辊成形精成形段有限元仿真分析

排辊成形已经被广泛的应用于直缝钢管生产中,由于其成形过程涉及明显的非线性,为研究带钢排辊成形精成形过程,建立了排辊成形机组的大变形弹塑性有限元模型,通过显式动力算法仿真,获得了精成形段带钢的等效塑性应变分布、几何变形规律、边缘纵向应变分布,并进行了实验验证。研究表明,排辊成形精成形段的较大塑性变形发生在带钢中心和边缘;从Fp1至Fp3,PEEQ曲线大致从W状分布向U状分布过渡;边部纵向应变在0.6%以内,未导致边部成形缺陷;几何形状从类U形向顶部开口的规则圆形过渡。     

辊弯成型中的纵向弯曲

纵向弯曲是辊弯成型中存在的普遍现象。由于辊弯成型过程的复杂性,孔型的设计和成型道次数目对纵向弯曲的影响仍然靠经验来确定。利用ANSYS/LS-DYNA软件中的显式动态有限元模块,模拟槽钢辊弯成型过程;并将模拟后的结果与实验数据进行对比;通过改变成型角的尺寸、成型道次的数目和成型底线布置,得到了不同情况下的纵向应变和下弯值,从而找出产品辊弯成型时纵向弯曲的规律,为槽钢辊弯成型设计提供了理论依据。     

工艺参数对简单断面型钢辊弯成型过程的影响

采用B3样条有限条法研究成型工艺参数（如弯曲角增量、带材厚度、材料屈服极限、翼缘长度、腹板宽度和机架间距等）对槽钢辊弯成型过程带材边部纵向薄膜应变峰值的影响。带材边部纵向薄膜应变峰值随着弯曲角增量、带材厚度、材料屈服极限、翼缘长度和腹板宽度增加而增加，随着机架间距的增大而减小。研究结果与辊弯成型过程中观察到的现象完全一致。     

带钢平整轧制残余应力场的二维数值模拟

本文采用非线性有限元软件ABAQUS对带钢平整轧制过程进行了二维建模,仿真分析了带钢屈服强度、厚度、应变硬化率与平整轧制后带钢厚度方向上纵向残余应力分布之间的关系。结果表明,入口带钢的屈服强度与厚度对平整轧制后带钢厚度方向上的纵向残余应力分布有较大影响;而带钢的应变硬化率对平整轧制后带钢厚度方向上的纵向残余应力分布影响较小。     

ERW直缝焊管成型装置的发展

简要介绍了ERW直缝焊管成型装置的产生和发展历程。详细阐述了ERW直缝焊管排辊成型的特点、主要生产工艺布置和设备组成、排辊成型的换辊与调整等。     

COMPUTER AIDED ANALYSIS FOR COLD ROLL FORMING THIN CHANNEL SECTION

1. IntroductionRoll forming is a general term used to describe a large class of continuous manufacturingprocess where a long strip of sheet-metal is deformed illto products with desired geometryby passing through a series of rotating rolls arranged in tandem[1]. A wide range of productsfrom medical equipmellt to office furniture is manufactured in this working method. Sincethe deformation process is complex, cold roll forming, to a large extent, has been developedon an empirical basis and from…     

激光复合织构焊管轧辊模具成形有限元模拟与试验研究

目的提高焊管成形质量,为激光复合织构轧辊模具产业化提供试验依据。方法通过数值模拟方法模拟焊管轧辊成形过程,获得不同摩擦系数组合下板料成形应力应变和径向厚度数据,并获得最优模具表面织构方案,为轧辊模具表面织构处理提供依据。依据数值模拟结果,运用激光表面织构技术对辊子模具表面进行复合织构加工处理,开展激光复合织构模具和未织构模具成形对比,并对成形件进行残余应力、应变、边缘减薄率等检测分析。结果数值模拟结果表明,下辊边缘区域应为减摩区,上辊边缘区域应为增摩区;应对下辊边缘区域进行激光微织构减摩,上辊边缘区域进行激光毛化增摩。成形试验结果表明,试验结果与数值模拟结果基本一致;与未织构模具相比,激光复合织构焊管轧辊模具优化了成形件的应力应变分布,降低了板厚边缘减薄率(5.06%),提高了成形件的均匀性(3.9%),成形件边缘区域形成了残余压应力。结论激光复合织构焊管轧辊模具相比未织构模具,可显著改善成形件的边缘稳定度和成形质量。     

Research on strip deformation in the cage roll-forming process of ERW round pipes

Cage roll forming is an advanced roll-forming technique to manufacture electric resistance welded (ERW) round pipes. In the cage roll-forming process, many small rolls are arranged along the outer surface of the deformable strip to bend the strip edge in a more smooth way. Furthermore, these small rolls can be used for forming pipes of different sizes. Therefore, cage roll forming can reduce roll change time and improve forming quality, as compared with the conventional step roll forming. However, very few studies can be found about cage roll forming, due to its complexity, and the industrial practice depends greatly on experience rather than science-based design today. In this work, the whole cage roll-forming process is simulated with the explicit elastic–plastic finite element method, and the strip deformation during the cage roll-forming process has been investigated in detail. Through the simulation, the “non-bending area” phenomenon is found, and the ranges of the non-bending area at different forming stands are obtained. In addition, the longitudinal strain at the inside edge and center are predicted, and by comparison, it can be known that the deformation of the strip edge is usually larger and edge buckling is most likely to occur at the entry sides of No.1–No.3 fin-pass stands. Finally, the circumferential length, opening distance and the profiles of the deformed strip are measured on the cage roll-forming mill. There is a good agreement between the experimental and simulated results.     

有限条法模拟直缝焊管成型过程

以结构分析有限条法为基础,基于固体力学有限形变理论的Ｕｐｄａｔｅｄ－Ｌａｇｒａｎｇｉａｎ法,建立了弹塑性大变形样条有限条法,并用于模拟直缝焊管的成型过程,获得了变形带材的三维位移场、应变场和应力场。分析结果表明,带材边缘部位是焊管成型过程的主要变形区,其应变、应力值的大小将直接影响焊管质量,是焊管生产中一个值得重视的问题。文中提出的方法可以有效地分析直缝焊管成型过程,并将用于分析其它开口冷弯型钢成     

Prediction of maximum initial strip width in the cage roll forming process of ERW pipes using edge buckling criterion

Cage roll forming is an advanced process for producing electric resistance welded (ERW) pipes. It is designed to improve the strip deformation and to increase the flexibility of production lines compared with the conventional roll forming of ERW pipes. One of the most important parameters of this process is the initial strip width. Accurate prediction of the initial strip width is vital for producing sound pipes with desired dimensional and geometrical tolerances. In this paper, cage roll forming process is simulated with the explicit elastic–plastic finite element method in the MSC Marc Mentat software. Simulation results show that by increasing the initial strip width, more circumferential length reduction is induced to the deformed strip in the fin-pass stands. This effect increases the difference of longitudinal strains at the edge and center of the deformed strip and consequently leads to a high longitudinal compression at the strip edge. Therefore, edge buckling will be unavoidable if the initial width is selected bigger than a specific limit. In order to predict the maximum initial width in cage forming process, an edge buckling criterion was introduced. The circumferential length and the horizontal distance between two deformed strip edges were obtained from the simulation and were compared with the experimental data from a production line. The comparison showed a good agreement and confirmed the finite element simulations.     

利用正交试验设计优化冷弯成形工艺参数

冷弯成形工艺参数的设计对冷弯成形产品质量有重要影响。本文对方矩形管冷弯成形过程中机架间距、摩擦因数和轧制速度的不同取值水平通过正交试验设计,利用Abaqus有限元软件的显式非线性动态分析对所设计试验仿真模拟,得到了每道次轧制过程中带钢边部最大纵向应变最小时各个道次3个工艺参数的最佳取值。并用优化后的参数进行仿真和验证,得到各道次带钢边部最大纵向应变比优化前要小,优化后第4~第10道次带钢纵向应变极值相对接近,产品边部拉伸小,并且边部拉伸分布比较均匀,有效改善了产品质量。