应用滑移线理论分析初轧变形区的应力分布

利用滑移线理论分析初轧变形区的应力分布，能避免初轧时轧件内部产生较大拉应力。提出一个切实可行的计算程序，能快速而准确地绘制初轧变形区内的滑移线场，并对该轧制条件绘制了应力分布曲线。为制定初轧机压下制度提供借鉴。     

中 厚 板 轧 制 过 程 的 数 值 模 拟

 基于LS DYNA仿真软件,采用显式算法和隐式算法相结合的方法,对中厚板轧制过程的热力耦合有限元模拟进行了研究。通过仿真,得到了中厚板的应力场、应变场及温度场的分布。根据分析可知轧件表面温度在轧制过程中有所上升,轧件内部到表面形成明显的温度梯度。轧件头部变形较剧烈,在轧制后外端存在明显的预应力区。模拟结果与实测结果比较一致,表明了该数值仿真方法的可靠性。     

A 3-D Differential Method for Solving Rolling Force of PC Hot Strip Mill

 According to the character of the deformation zone on pair cross rolls, which is different from the regular 4-high mill, there are longitudinal and transverse two-way shear deformation in the deformation zone, the character of metal particles flowing velocity is more complicated than normal rolling. Comprehensive influences of normal stress and shear stress in rolling direction, width direction and thickness direction are considered. Establish the rolling force calculation model of PC hot strip mills. After the longitudinal and transverse discretization of deformation zone, the longitudinal and transverse distribution of rolling force is worked out by the differential method, then calculate total rolling force. Calculated results are verified by experimental data.     

基于奥洛万微分方程的变厚度LP板轧制力模型

 纵向变厚度LP板是钢铁减量化轧制中的典型产品。轧制力模型是变厚度轧制过程关键模型,直接决定产品尺寸精度。通过引入剪切摩擦与奥洛万平衡微分方程,建立变厚度轧制LP板中各个变形区的应力表达式。改变轧制参数以观察变形区内轧制力变化规律,理论计算结果表明,轧制变形区轧件出口位置由楔形角决定,入口位置及轧制力峰值则与压下量有关;同一压下量下趋厚轧制力峰值小于普通轧制,趋薄轧制力峰值大于普通轧制。     

粗轧过程轧件表面裂纹演变行为热力耦合有限元分析

 连铸坯可能出现表面裂纹,其在轧制过程中的演变行为严重影响着轧制产品的质量。本文采用热力耦合有限元方法对轧制过程轧件表面裂纹演变行为进行了分析。获取了轧制过程中轧制变形区内轧件表面裂纹形状变化规律、裂纹附近区域应力场和温度场分布场分布情况。计算结果表明在轧制入口区域,裂纹逐渐闭合,然而,在轧制出口区域,裂纹又重新扩展开,裂纹尖端处呈现拉应力状态。同时,发现变形区内裂纹尖端发生温度成双峰变化规律。     

State of stress in the deformation zone during rolling of high-strength plate steel

A new mathematical model is developed for the state of stress in the deformation zone for plate rolling, including rolling under controlled conditions at a low temperature in the last passes. The stick zone during plate rolling is shown to account for 88–99% of the deformation zone, and the fraction of elastic regions in the deformation zone in the last passes at low temperatures can reach 12%. When the stick zone and elastic regions of the deformation zone are taken into account, the roll-force calculation error is less than 5–6.5%. The model developed can be used to optimize plate-rolling conditions, including the conditions of integrated deformation-thermal production.     

Finite Element Analysis for Effect of Roll Radius on Metal Deformation of Hot Rolling Plate

Theeffectofrollradiusonrollingforcehasbeenstudiedlargely ,buttheeffectofrollradiusondeforma tionofrollingpieceandontexturewasmentionedlit tle[1] .Therollradiusmayhaveaspecialinfluenceonthedeformationofrollingpiecebyaffectingtheformofdeformationzoneandaddi…     

高精度重轨定径的实验与三维应变场、应力场分析

为了提高重轨的断面尺寸精度，适应我国高速铁路建设对重轨的需求，本文对重轨进行了四辊万能孔型定径轧制实验研究。可将轨高和轨头宽度的波动控制在±０．０５ｍｍ以下。采用ＡＮＳＹＳ有限元分析软件，对重轨定径进行了三维变形物理场分析，得出了在位移载荷下的弹塑性应力、应变和位移分布，结果表明用ＡＮＳＹＳ计算分析的结果与实际定径实验的结果相符。     

含铌HSLA钢板带热连轧过程非均匀应变的数值研究

 利用ANSYS/LS DYNA建立了板带轧制过程的三维热力耦合有限元模型,通过有限元模型探讨了轧件入口厚度、轧件温度、工作辊直径、压下率和化学成分中的铌含量对变形区应变分布的影响。模拟结果表明,这些因素都不同程度地影响轧件厚度方向的应变分布,对于试算的CSP流程,适量增加铸坯厚度,并在较靠前的机架分配较大的压下量有利于提高轧制过程的应变均匀性。     

带夹层不锈钢复合板异步轧制力数学模型研究

 为实现带夹层复合板异步轧制力的预报,对直接添加薄板作为中间层的不锈钢复合板进行受力分析,依据各层金属变形特点以及轧件摩擦力方向的变化,将轧制变形区划分为5个分区,考虑复合板单元体截面法向应力与剪应力在各层金属间的线性分布,借助各个分区力平衡方程,建立了带夹层复合板异步轧制力数学模型;研究了剪切屈服应力比、辊径比、摩擦因数比对各层单元体应力分布的影响以及不同压下率下中性点和连接点的位置变化规律;运用MSC.Marc有限元仿真软件,对316L/Ni/EH40复合板进行了5道次异步轧制仿真,轧制变形区受力状态与理论模型基本一致,各道次轧制力大小与理论计算值误差在10%以内,结果表明,本模型可为带夹层复合板异步轧制力精准预报提供理论指导。     

平整机辊系变形的有限元分析

通过对辊系变形的模拟,分析了轧制条件下对工作辊弯曲变形、支撑辊弯曲变形及接触应力的影响,借助大型有限元分析软件ANSYS的手段,对辊系进行了弹性力学结构分析,得出了在轧制过程中辊系的变形情况及载荷分布等详细直观的分析结果。     

H型钢开坯轧制四道次有限元模拟

利用有限元分析软件ANSYS／LS－DYNA，对H型钢开坯轧制四道次进行了有限元模拟。详细介绍了有限元模型的建立，材料模型的选择，单元的选择以及网格的划分。得到了各道次轧件的模拟变形结果。对轧件的变形和轧制区内应力场的分布进行了深入的分析，为轧制异型断面型钢的显式动力学有限元模拟提供了参考。     

超高强钢冷轧过程轧制力计算的改进模型

 为了解决采用圆弧模型计算超高强钢冷轧过程轧制变形区轧辊压扁曲线误差较大的问题,充分考虑到超高强钢的轧制特点,通过分析不同压扁半径下轧辊压扁曲线的变化规律,构造出新型轧辊压扁曲线函数模型,给出了该函数中轧制变形区接触弧长特性参数与轧辊压扁曲线特性参数的求解方法。基于此,根据弹塑性理论中的变形与应力关系,推导了入口弹性变形区、塑性压下变形区以及出口弹性变形区单位轧制压力分布计算过程,建立了超高强钢冷轧过程总轧制力计算模型。并将其推广应用到某钢厂2030冷连轧机组,验证了该模型的计算准确度。结果表明,超高强钢冷轧过程轧辊压扁曲线用二次函数表示,更能准确反映轧辊压扁状态,其计算结果与实际值具有较高的吻合度。同时,为冷连轧机组生产超高强钢产品极限轧制能力的评估与轧制规程的制定提供了理论依据。     

精确接触边界条件下热轧带钢轧制力的仿真研究

在流面条元法基础上，将带钢与轧辊的接触面视为三维曲面，结合塑性力学中斜面上应力的求解法，给出了接触表面上的精确应力边界条件，建立了单位轧制压力与变形区内部应力的关系，实现了对板带轧制三维应力和变形的精确分析和计算。热轧带钢轧制力的仿真研究结果表明，新算法(改进算法)的计算精度高于旧算法。     

考虑焊缝性能的冷轧过程有限元仿真分析

焊缝区材料与基材的力学性能通常存在一定差异,这种力学性能的差异会影响冷轧过程,造成轧制力的变化。采用有限元软件ANSYS LS-dyna,就焊缝对冷轧过程的影响进行了仿真分析。结果表明,与带钢基体相比,焊缝区残余应力、应变以及轧制力都产生不同程度的突变。     

钢铜复合材料深加工变形力能参数研究

利用压力试验机和二辊轧机，在外力和压下方向平行于复合面的变形方式下进行了实验提出了确定变形区应力状态系数Ｑ＿ｐ的方法，建立了Ｑ＿ｐ数学模型。并对Ｑ＿ｐ模型进行了实验验证，表明模型精度较好。     

宽厚不锈钢复合板轧制力计算与参数影响分析

 对宽厚不锈钢复合板层间真空热轧制变形过程进行受力分析,将热轧变形区分成I、II两个区间,运用主应力法建立各个区间的力平衡方程,根据边界条件和屈服准则求出各变形区的长度和各变形区所受压力,建立轧制力计算数学模型,在此基础上分析轧制工艺参数对宽厚不锈钢复合板轧制区间内不同应力分布的影响规律。将实际参数代入轧制模型计算公式,应用Matlab编程求得理论计算值,并与实测值进行比较。研究结果表明：轧制力模型可用于预测轧制力的大小,满足工程要求,轧制复合过程研究有助于优化成形工艺、预测产品性能,为今后此类材料的研究开发提供了参考依据。     

板带钢轧制的有限元模拟分析

为了指导板带钢的实际生产,减少试轧次数,故采用了有限元软件ANSYS8.0建立了板带钢的轧制模型.通过接触分析的方法对高温条件下板带钢的轧制过程进行了模拟仿真,并对轧制过程中板带钢的变形及应力分布作了分析.结果表明,模拟与实测数据基本吻合.     

Permissible Minimum Thickness in Asymmetrical Cold Rolling

The minimum rolling thickness in asymmetrical rolling was analyzed compared with that in symmetrical rolling. The differential equilibrium equations on forces were established to calculate the asymmetrical rolling force equation by slab method. An implicit expression of the minimum rolling thickness was then derived from the rolling force equation and Hitchcock equation. The results show that permissible minimum rolling thickness of asymmetrical rolling only exists within a specific range of cross-shear ratio, which is termed the cross-shear zone proportion of the whole deformation zone. Numerical computation was carried out to obtain a discrete solution of the minimum rolling thickness. Experiments were designed to investigate the influence factors on cross-shear ratio. Finally, experimental results prove the correctness of the improved formula given.     

Improving the quality of rolled pipe steel products by minimizing the bending of the ends of plates

The causes of the vertical bending of the front ends of plates during hot rolling are revealed. A finite-element mathematical model is developed to describe the state of stress of the metal in an asymmetric deformation zone with allowance for solving a temperature problem, and the model is adapted to the conditions of the 5000 rolling mill in OAO MMK. It is found that, in rolling with mismatched work roll speeds, the direction of bending of the front strip end is determined by the strip thickness and the deformation zone shape. The main cause of the bending of the front plate end at the stage of finishing stage of rolling is shown to be the difference between the roller bed level and the rolling line. New asymmetric deformation regimes are developed with allowance for the effect of the deformation zone shape on the direction of bending of the front strip end. The developed technological regimes of asymmetric rolling make it possible to decrease the mill downtime because of the bending of the breakdown bar ends and to reduce the metal volume rejected because of violated temperature regimes of the thermomechanical treatment of plates.