薄带平整轧制时轧制压力模型的研究

考虑到轧辊的弹性变形以及轧件的弹性变形,建立了一套新的薄带平整轧制时的轧制压力模型。在模型中,对于一般薄带,考虑到停滞区的不对称性,采用混合摩擦理论分析了变形停滞区的摩擦力分布;而对于极薄带材,根据平整时塑性区相对弹性区缩小,摩擦力模型中的停滞区的范围并不止于塑性区,有可能扩大到弹性变形区这一特性,对相应的单位轧制压力分布情况进行了详细推导。同时,为了验证相关模型的准确性,采用该模型对宝钢1550CAL平整机相关典型规格产品轧制压力进行了理论计算,并在线实测出相应的轧制压力,其计算结果与实测值很好吻合,完全达到了工程上所需要的预报精度要求。因而该模型具有重要的理论意义和实用价值,可作进一步的推广与应用。     

冷轧薄板接触弧长的确定及轧制压力计算

本文在计算冷轧薄板接触弧长度和轧制压力时,不仅考虑轧辊弹性变形,而且也考虑轧件弹性变形。把变形区分为入口弹性区、塑性区和出口弹性区。应用弹性力学基本方程、塑性条件和平板压缩理论导出了入口弹性区和出口弹性区单位宽度轧制力公式及塑性区平均单位压力公式。应用弹性接触理论和变形区的几何关系导出了计算冷轧薄板接触弧长度公式。最后给出了考虑轧辊和轧件弹性变形时计算冷轧薄板的总的轧制力公式。该公式不仅适用于一般工程计算,而且也能为在线控制的电子计算机提供较为精确的轧制力数学模型。     

冷轧薄钢板"湿法"平整的轧制压力计算

平整是使冷轧薄钢板获得合理表面形貌的关键工艺。平整轧制压力的预测与控制直接影响钢板平整后的表面质量。本文作者采用刚性、弹塑性、全滑动和边界润滑等不同模型，进行了平整轧制压力预测模型的理论分析与模拟实验研究。结果表明：当矿井下量小于5%后，轧辊的弹性变形和钢板的弹性恢复对轧制压力的影响很大，不能忽略；采用边界润滑弹塑性模型计算得到的平整轧制压力较边界润滑刚性模型更接近实验值（相对误差减小约20%）。     

基于非圆弧理论的平整机轧制力简化模型

针对目前带钢平整机轧制力模型的缺点,综合考虑带材的弹性变形与塑性变形,基于非圆弧轧辊理论的大量计算结果,回归得到一套冷带钢平整机轧制力简化模型。该模型可用于干平整或湿平整轧机设计、轧制规程制定。4个典型算例的计算结果表明,简化模型与非圆弧轧辊理论计算结果一致。最终通过2套平整轧机的实测轧制力验证了简化模型的正确性。     

带材轧制过程应力及变形的计算机仿真

用三次样条流线条元法分析带材的三维塑性变形,用分割模型影响系数法分析辊系的弹性变形,用BP神经网络方法对轧后带材板形进行模式识别,将三者联立,对900 mm HC轧机冷轧带材轧制过程进行了计算机仿真,得到了较为详细的应力及变形的仿真结果。仿真实例表明,提出的方法和模型符合实际,对三维轧制理论、板形理论及控制技术的发展有重要意义。     

板宽对轧辊受力分布的影响规律

轧辊受力分布的形态直接影响轧辊的弹性变形和轧件的出口板凸度.基于影响函数法,对轧机辊系受力和轧辊弹性变形进行计算分析,研究了轧制过程中板宽对轧制压力、辊间压力横向分布的影响.分析表明,边部轧制压力先随着板宽的增大而增大,达到某极值点后又逐渐减小;而随着板宽的增大辊间平均压力增大,压力分布变得不均并向轧辊端部集中;这些规律为不同板宽轧件的轧制规程安排、轧辊磨损的计算分析以及轧件出口板凸度的计算模型与控制提供了基础.     

双辊连续铸轧过程中轧制界面接触压力切块法建模与数值模拟

铸轧区可分为冷却区，铸造区和轧制区3个物理区。利用切块法分别推导出了铸造获轧制区变形过程静力平衡微分方程。在温度分布线性假设的基础上建立了轧制区变形抗力的简化模型，并在铸造区变形抗力的模型中引入了固相百分数来表征固态金属对变形抗力的影响。对铸造区利用龙格－库塔法对微分方程进行数值求解，而对轧制区则根据混合摩擦条件求出微分方程的解析解，从而建立了铸轧区轧制压力模型，利用该模型对轧制压力进行数值计算，计算结果与实测数据相吻合。     

基于影响函数法的轧制压力横向分布规律分析

轧制压力横向分布直接影响轧辊的弹性变形和轧件的出口厚度分布。文中基于影响函数矩阵法,对轧机辊系受力和弹性变形进行计算分析,研究轧制过程中弯辊力和压下率对轧制力横向分布的影响,揭示轧制压力横向分布系数与弯辊力呈近似线性增长、与压下率呈近似线性减小的规律。分析表明,通过调节弯辊力或在轧制规程中改变压下率设定,可改变轧制压力的分布。为轧制压力横向分布函数的在线快速计算和板凸度控制模型的建立提供基础。     

1200mm平整机轧制压力的图表法计算

本文根据平整时压下量小的特点，采用考虑了轧件弹性变形的Ｂｌａｎｄ－Ｆｒｏｄ公式并结合图表，在设计沈阳薄板厂１２００ｍｍ平整机时其对轧制压力的进行了计算。     

二次冷轧过程变形区油膜厚度模型

为了定量预报二次冷轧过程轧制变形区油膜厚度,结合二次冷轧机组乳化液直喷系统的设备与工艺特点,分析了带钢表面析出油膜、工作辊表面附着油膜的形成机理,建立了一套二次冷轧过程轧制变形区带钢上下表面油膜厚度模型,定量分析了乳化液流量密度、乳化液浓度、乳化液析出距离、轧机入口轧制速度、轧制咬入角、带钢入口变形抗力、后张力、轧制油初始动力黏度、轧制油压力黏度系数对轧制变形区带钢上下表面油膜厚度的影响,并将该模型应用到某1220二次冷轧机组的生产实践,编制出了相应的模型计算软件,实现了二次冷轧过程变形区油膜厚度的预报,为二次冷轧过程润滑性能的控制奠定了理论基础。     

冷轧带钢的平整轧制

论述了冷轧带钢平整的目的,平整主机机型及适用性。重点介绍了平整轧制对带钢性能的作用及影响。     

Control Method for Steel Strip Roughness in Two-stand Temper Mill Rolling

How to control surface roughness of steel strip in a narrow range for a long time has become an important question because surface roughness would significantly influence the appearance of the products...     

双机架平整机轧制力智能模型研究

针对双机架平整机的生产工艺特点，在引入延伸率分配系数模型的基础上，提出先对带材进行规格划分，然后利用大量同规格现场轧制数据，采用Powell优化算法计算变形抗力、摩擦因数等主要轧制工艺参数的方法。为满足轧制力预报的实时性要求，建立了BP神经网络模型来预报上述轧制工艺参数，将轧制压力的短期自适应与轧制工艺参数长期自学习相结合，建立了双机架平整机轧制压力预报模型。将该模型运用于宝钢某厂1220双机架平整机的生产实践，大大提高了轧制力预报精度。     

Mathematical model for cold rolling and temper rolling process of thin steel strip

A mathematical model for cold rolling and temper rolling process of thin steel strip has been developed using the influence function method. By solving the equations describing roll gap phenomena in a unique procedure and considering more influence factors, the model offers significant improvements in accuracy, robustness and generality of the solution for the thin strip cold and temper rolling conditions. The relationship between the shape of the roll profile and the roll force is also discussed. Calculation results show that any change increasing the roll force may result in or enlarge the central flat region in the deformation zone. Applied to the temper rolling process, the model can well predict not only the rolling load but also the large forward slip. Therefore, the measured forward slip, together with the measured roll force, was used to calibrate the model. The model was installed in the setup computer of a temper rolling mill to make parallel setup calculations. The calculation results show good agreement with the measured data and the validity and precision of the model are proven.     

Mixture Lubrication with Emulsions in Cold Rolling

A mixture model of lubrication in cold rolling with two adsorbed layers on the solid surfaces and an emulsion layer between them has been developed. The elastic deformation of the strip and the rolls is considered. A series of simulations using this model is carried out, and this model predicted that the value of the inlet film thickness is in good qualitative agreement with the experimental results. There exists a range of roll speeds that provides sufficient friction to perform the rolling process without front tension under the merged conditions and lower roll speeds. At high roll speed, the two adsorbed layers are separated by the emulsion layer, and the pressure hill disappears due to the smaller surface shear stress acting on the strip, so that rolling is no longer possible unless accompanied by a front tension.     

Experimental measurements of load and strip profile in thin strip rolling

Experiments are described in which plasticine strips are rolled using elastomer rolls. Conditions cover the range from “thick strip” behaviour, in which roll elastic deformations are small, to “thin strip rolling”, in which elastic deformations of the rolls are very significant. Results provide the first direct experimental confirmation of the thin strip rolling model proposed by Fleck et al. (Proc. Instn Mech. Engrs B206 (1992) 119–131). Strip profiles clearly show a short region of reduction at the inlet to the bite and a central region which is relatively flat, in accord with the theory. The profiles do not however show a short region of reduction at the exit as predicted. For intermediate strip thicknesses the measured loads are in reasonable agreement with theory. For the thinnest strips, although the form of the dependence of load on reduction and inlet strip thickness is as predicted by theory, the measured loads are almost an order of magnitude lower than predicted. It is suggested that this is caused either by differences between the assumed rigid–perfectly plastic strip and the real constitutive behaviour of the plasticine, or by errors in treating the rolls as elastic half-spaces, an approximation which is accurate for industrial metal rolling, but is not good for the conditions of these experiments.     

热带钢连轧多场耦合演变过程有限元分析

根据物理冶金组织演变规律和经验公式，开发了金属热变形过程耦合组织演变的计算模块。结合某厂2050热带钢连轧工艺过程，利用非线性刚塑性有限元法，建立热连轧过程热、力、组织的多参量耦合仿真模型。运用该模型对2050现场实际轧制过程进行模拟计算，分析了轧制过程轧件变形场、温度场及显微组织的演变规律。模拟得到的轧制力能参数、温度、组织分布与实测数据基本一致。     

STUDY ON STRIP AND ROLL DEFORMATION COUPLING OF COLD STRIP ROLLING ON 4-H MILL

ＳＴＵＤＹＯＮＳＴＲＩＰＡＮＤＲＯＬＬＤＥＦＯＲＭＡＴＩＯＮＣＯＵＰＬＩＮＧＯＦＣＯＬＤＳＴＲＩＰＲＯＬＬＩＮＧＯＮ４ＨＭＩＬＬ①ＬｉｕＨｏｎｇｍｉｎＨｕＧｕｏｄｏｎｇＹａｎｓｈａｎＵｎｉｖｅｒｓｉｔｙＡｂｓｔｒａｃｔＴｈｅｃｏｌｄｓｔｒｉｐｒｏｌ...     

柔性薄膜太阳能电池用精密不锈钢基板冷轧成形的数值模拟

利用有限元方法,研究了压下量及前后张力对柔性薄膜太阳能电池用不锈钢基板轧制过程中应力分布的影响.结果显示,适当增加压下量有利于表面应力的均匀分布,且可减少轧制道次,但过大压下量容易导致不均匀塑性变形;采用后张力稍大于前张力的轧制工艺,可使基板应力分布趋向均匀,当前后张力值分别为40 kN和58 kN时,应力分布均匀且板内最大等效应力值最小.研究表明,采用后张力稍大于前张力、压下率控制在30％以内的轧制工艺,可保证薄板应力值较小且分布均匀.最后,在模拟结果的指导下,成功轧制得到厚0.25 mm的不锈钢基板,其厚度分布与模拟结果基本一致,且粗糙度满足基板的使用要求.