热带钢粗轧机组温度场有限元模拟

针对宝钢2050mm热轧带钢粗轧机组的轧制工艺条件，采用有限元法建立了热应力耦合二维温度场有限元仿真模型，并模拟了全过程。给出了带钢沿厚度方向各处温度随时间的变化曲线，得出了高压水除鳞、接触传热对板材温度场的影响模型。同时给出了各道次轧制力计算结果。模拟得到的粗轧段出口温度及轧制力与宝钢现场实测数据值相吻合。     

孔型立辊调宽轧制的三维刚塑性有限元研究

采用刚塑性有限元法(FEM)建立宝钢2050粗轧区孔型立辊调宽过程轧制模型。计算所得多块带钢轧制力值与现场实测结果吻合良好,模拟的带钢头尾形状与现场实际结果吻合也很好,并建立立轧稳态狗骨形状计算的数学模型。同时研究得出立辊孔型角度对狗骨高及轧制力的影响规律。     

基于影响函数法的冷轧带钢轧制力计算

根据经典轧制力模型 ,在考虑轧制力模型与轧辊压扁模型耦合的前提下 ,开发了基于影响函数法的冷轧带钢轧制力计算程序 ,并用实际生产中的采样数据模拟计算了HC轧机各道次的轧制压力分布和总轧制力 ,将所得计算结果与现场实测数据进行比较。结果表明 :所得轧制力计算结果与实测值相近 ,轧制压力分布与实际相符 ,为HC轧机板形控制提供了一种计算轧制力的有效方法。     

中厚板轧制过程平面形状控制道次轧制压力分布数值分析

采用显式动力学弹塑性有限元方法和几何模型更新技术,对中厚板轧制过程中平面形状控制道次进行了模拟。对平面形状控制道次中3个阶段轧制压力分布、轧制力变化进行了分析,所计算平稳阶段轧制力值与实测轧制力值吻合较好。     

热连轧板带精轧变形有限元数值模拟

应用CAE大型通用有限元分析软件ABAQUS,采用热力耦合大变形模拟方法,对热连轧板带7道次精轧过程进行了数值模拟。以某钢铁厂现场实际生产数据为基础,设计板带连轧仿真模型,并定义工艺参数,模拟了板带热连轧精轧机组的生产过程。针对板带在热连轧过程中的变形、应力应变云图和金属流动规律做了模拟分析与计算。计算结果表明,模拟计算数据与现场实测数据基本吻合,为热连轧板带的生产工艺制定提供了可靠的数值模拟依据。     

基于FEM-ANN的高强度冷轧带钢平整轧制力预测

为了提高平整轧制力的预报精度，采用有限元法(finite element method, FEM)与人工神经网络(artificial neural network, ANN)相结合的方法，对DP980和CP1180超高强冷轧带钢在平整轧制过程中的轧制力进行预测。通过建立平整轧制过程的数学模型，利用有限元法设计了不同工况下的数值模拟试验，为神经网络模型生成训练数据。将摩擦因数与轧制力关联进行迭代优化后作为神经网络模型的输入参数。该轧制力预测方法计算迅速，预测误差在10%以内。     

异形管两辊双道次成型过程研究

利用显示动力学有限元法模拟了异形管两辊双道次成型过程,结合实验对异形管两辊双道次成型过程中轧制道次与轧制力的关系、轧制力与轧制速度的关系、轧制力与壁厚的关系、轧制力与摩擦系数的关系、轧制力与辊轮大小的关系等方面进行了分析,模拟结果与实验结果相符.研究结果为实际生产提供了有益依据.     

热带精轧过程中温度变化规律的研究

为研究热连轧带钢终轧温度变化规律,给出了带钢轧制过程温度计算模型,分析了轧制速度、工作辊材质、带钢材质和工作辊温度对变形温升、接触温降和摩擦温升的影响,从而得到带钢轧制过程中温度变化的影响规律,为建立高精度热连轧带钢温度控制模型提供了理论依据.     

基于负荷均衡的高速线材轧机孔型优化设计

采用大型非线性有限元软件MSC.Marc,通过三维热力耦合弹塑性有限元方法对高速线材中轧区五机架热连轧过程进行了模拟,以各轧机相对等负荷为目标函数,运用Visual FORTRAN语言对MSC.Marc进行二次开发,准确计算了现场及孔型优化后的各道次轧制力和轧制力矩,相对负荷由现场的3.46%～133.91%减小到2.62%～19.3%,使生产工艺更加合理,对实际生产具有重要的指导意义.     

高温合金钢中厚板热轧有限元模拟

根据热模拟实验机上获得的试验数据,在MARC软件中建立了高温合金钢IN718的材料数据库。采用弹塑性热力耦合有限元法模拟了高温合金钢IN718中厚板多道次热轧过程,得到了各道次轧制力。模拟结果表明,高温合金IN718的轧制力较普通钢板大很多,有限元模拟值与工程计算值吻合很好。     

基于GA-PELM的板材热连轧轧制力预测

在板材热连轧过程中,轧制力的计算精度直接影响板带钢的实际厚度,也是实现精准在线控制的前提.然而,由于实际的轧制过程受多种因素影响,使用传统模型进行预测的精度往往比较低.为了提高轧制力的预测精度,提出了并行异构极限学习机(PELM)的轧制力预测模型,该模型学习速度快且泛化能力强,同时为了保证模型的稳定性,采用遗传算法(G...     

带钢热连轧精轧过程轧制力模型研究

在精轧过程中变形区不仅存在粘着区,而且存在着滑动区,但是大多数轧制力计算模型都从变形区全粘着出发,采用以西姆斯公式为基础的简化回归公式。本文将轧辊与带钢接触表面分为粘着区和滑动区;考虑了摩擦力在轧制过程不断变化,得出了不同轧制道次下摩擦力影响系数的回归公式;并且考虑了不同钢种轧制时残余应变对变形抗力的影响,建立了精轧轧制力预测模型。通过与某钢厂实测数据对比,该预测模型具有较高的计算精度。     

板带轧制过程的三维耦合有限元分析

对板带轧制过程进行严密的三维分析是研究轧制参数对轧后板带尺寸、板形和机械性能的影响 ,从而实施有效控制的基础。本文简要回顾了板带轧制过程三维数值模拟的研究进展 ,提出了一个分析板带轧制过程的耦合有限元模型 ,其中 ,轧件塑性变形采用刚塑性有限元法计算 ,辊系弹性变形采用弹性有限元法计算。计算实践表明 ,该模型具有良好的精度和较高的效率。     

I型扁钢轧制过程数值模拟

本文I型扁钢的生产坯料为钢带经卸卷、分条轧制后的窄钢条。采用有限元软件Msc.Marc建立了规格为25 mm×5 mm×3 mm的Q235 I型扁钢4道次热连轧的弹塑性有限元模型,研究了轧件在轧制过程中的变形情况、等效应力、等效塑性应变的变化规律。结果表明：轧件在立轧道次会出现轻微的狗骨形,平轧道次会出现轻微的单鼓形;轧件横断面的中间部位等效塑性应变较大;轧件边角部等效应力较大,轧制过程中易出现质量缺陷。     

Analysis of asymmetrical hot strip rolling by the slab method

Two analytical models based on the slab method are proposed to examine the behavior of sheet at the roll gap during the asymmetrical hot strip rolling process. In model I, the effect of shear stress in vertical plane at the roll gap is considered, whereas this effect is neglected in model II. Neutral points between rolls and strip, rolling pressure distributions along the contact art length of rolls, rolling forces, and rolling torques can be calculated easily by these proposed analytical models. The results including rolling pressure distributions, rolling forces, and rolling torques by both models are compared. The rolling pressure distribution predicted by model I shows that a “pressure well” develops in the cross shear region. On the other hand, no “pressure well” is predicted in model II. Furthermore, the rolling forces predicted by model I are always lower than those measured in the experiment, whereas those predicted by model II are always higher. However, the averages of the values predicted by model I and II are in fairly good agreement with the experimental data. Thus this analytical approach can offer useful knowledge in designing the pass schedules of the asymmetrical hot strip rolling processes.     

板带轧制在线控制模型的研究

为解决板带轧制高速高精度在线模型问题,文章基于能量变分原理,研究了一种快速数值算法。该法将变形区划分为有限离散单元,考虑剪切变形作用,建立了高速计算模型,在平面变形条件下实现了对轧制力的仿真。计算结果与实测值、Marc有限元计算结果有很好的吻合。通过对某厂五机架冷连轧的分析,模型可在0.3s内完成全部计算。该算法对深入研究冷热态连轧过程在线控制具有重要实际意义。     

A three-dimensional finite element method for a nonisothermal aluminum flat strip rolling process

The purpose of this study is to develop a three-dimensional coupled thermo-elastic-plastic finite element model of nonisothermal rolling and analyze the strip curvature caused by the difference in the heat transfer boundary conditions of the upper and lower rollers. The difference in the rotation speed between the upper and lower rollers was utilized in an attempt to correct the aforementioned curvature in hot rolling due to unsymmetrical cooling conditions. In addition, the changes in shape, temperature field, and strain field of the strip during the various stages were analyzed and can be used to obtain the lateral plastic flow of the strip. As for the aspect of heat transfer, the various possible boundary conditions in the actual hot rolling were considered, which include the convection boiling of the air and water, and the radiation loss. Then, the three-dimensional finite difference heat transfer equation is derived according to the concept of heat balance. As for the determination of the direction of tangential friction force, this study also developed a modification algorithm to adjust to the three-dimensional rolling process. After a comparison with the experimental data in Ref 8 and 15, and the simulated temperature distribution in Ref 17, the partial results obtained from the computation by the numerical analytical model verify that the theoretical model and computer programs established in this study are reasonable. This study shows that hot rolling can greatly reduce the rolling force and strain rate with the early appearance of plastic deformation, and the distribution of temperature field is basically affected by the heat transfer boundary conditions. However, unsymmetrical heat transfer boundary conditions will cause unsymmetrical rolling forces of the upper and lower rollers and cause strip curvature; this condition can be corrected by the difference in the rotation speed of the rollers.     

1 200 MPa级冷轧先进高强钢轧制稳定性的分析及控制

针对1 200 MPa级冷轧先进高强钢轧制不稳定问题,对热轧原料组织性能均匀性、冷轧压缩比、冷连轧机组轧制策略等进行了分析。结果表明,热轧工序投入边部加热器,采用分段冷却等手段,可有效降低热轧原料头尾部组织性能差异,保证通卷性能均匀,进而保证通卷轧制过程稳定;通过优化冷连轧机组压缩比,可有效降低材料本身的加工硬化强度,进而避免连轧机组后面机架的轧制超负荷情况;通过优化冷连轧机组轧制策略,可保证轧制过程中各机架均匀变形,避免出现轧制力差异较大的情况,进而保证轧制过程稳定。采用上述措施,1 200 MPa级冷轧先进高强钢轧制力控制在约15 000 kN,厚度精度控制在±0.06 mm以内,可保证该级别高强钢的稳定轧制。     

ASR work roll shifting strategy for schedule-free rolling in hot wide strip mills

In order to meet the requirement of schedule-free rolling (SFR) for wide non-oriented electrical steel production with a large number of the same width strip rolling campaigns, ASR (asymmetry self-compensating work rolls) shifting strategies for different rolling schedules are studied. According to the actual rolling process, the work roll wear prediction mathematical model for non-oriented electrical steel sheets and a 3D finite element model for roll stacks are established. The effects of the shifting step and the shifting rhythm on the ASR wear contour and the loaded roll gap profile within the entire rolling campaign are analyzed. The reasonable ASR shifting strategies for different rolling schedules are developed. In comparison with the conventional work roll contour of K-WRS mill, the self-maintenances of roll contours for ASR reach to more than 88%, the rate of the measured strip crown less than 45 μm increased from 41.8% to 94.9%, and the rate of the measured strip crown larger than 52 μm decreased from 32.6% to 2.0% by industrial test on the production of the same strip-width for wide non-oriented electrical steel sheets in the 1700 mm hot strip mill of WISCO. The ASR technology has applied to the production successfully.     

基于流面条元法的热带钢连轧仿真分析

根据流面条元法 ,对 145 0mm六机架热带钢连轧进行了数值仿真。得到了各道次单位轧制压力、前后张应力和出口横向位移的分布。仿真结果表明 ,轧后带钢侧面呈鼓形 ,与实际情况一致。各道次的后张应力和前张应力有类似的分布规律。各道次总轧制压力的计算值和实测值很接近。仿真实例表明 ,流面条元法是一种模拟板带轧制三维变形的实用的工程数值方法。它具有计算量较少 ,适用范围较宽的特点。仿真结果对热带钢连轧工艺规程的制定具有指导意义。