冷轧平整板形控制工艺探讨

介绍了平整过程中影响板形缺陷的因素,提出了解决平整过程中板形缺陷的主要因素是轧辊的辊型控制,并分析指出了生产实际中可通过合适的原始辊型凸度、调整液压弯辊装置、倾斜轧辊以及调节轧制压力和带钢张力来改善平整板形的控制方法。     

热轧平整工程轧制力计算研究

针对一种可用于工程轧制力计算的平整轧制压力模型,通过对现场大量实测数据的回归分析,提出了按照平整入口厚度、平整延伸率、轧制速度、工作辊直径四个参数对实测数据进行分层筛选并计算钢种系数、工况系数的方法。结果表明,该方法获得的轧制力计算值能够与现场实测数据很好的吻合,误差均在10%以内,可用于热轧平整机轧制力的预报。     

双机架平整机组平整液参数优化设计

在大量的现场试验与理论研究的基础上,充分结合双机架平整机组的设备与大延伸率湿平整轧制的工艺特点,以润滑油膜厚度、摩擦系数、传热系数等参数为桥梁,把平整轧制功率与平整液的冷却能力相平衡作为目标,提出了一套适合于双机架平整机组、大延伸率湿平整轧制过程的平整液参数综合设定技术,并将其应用到某厂1220双机架平整机组进行现场试验,取得了良好的试验效果,创造了良好的经济效益,具有进一步推广应用的价值.     

用CSP热轧卷生产的冷轧退火平整板卷的屈服强度问题

用CSP热轧卷生产冷轧退火平整板卷时遇到的最突出的问题是屈服强度偏高,导致成形性不良.从再结晶规律、退火工艺、平整工艺、酸洗轧制线卷取张力、热轧工艺、化学成分等方面进行了系统研究,解决了CQ、DQ级冷轧退火平整产品材质偏硬,冲压开裂这一质量问题.     

平整过程中异步轧制轧制压力计算模型

平整过程中由于带钢下表面平整液滴落导致带钢出现上下表面摩擦因数不同的异步轧制现象,使用平整过程的轧制压力模型预报平整异步轧制过程中的轧制压力时精度不高。为此,针对普通工程适用的平整轧制压力模型计算平整异步轧制轧制压力误差较大的问题,提出适用于异步轧制的轧制压力计算方法。考虑到异步轧制的工艺特点与设备的实际工况,首先分析带钢上下表面润滑条件差异性和受力变形情况,建立变形区的平衡方程和单位轧制压力计算方程。其次研究了异步与同步轧制上下轧辊压扁的差异性,根据上下轧辊轧制过程中变形的几何关系和弹塑性力学理论,确定了变形区各参数的计算方法。在此基础上,采用迭代方法提升计算模型精度,建立了适用于平整机组异步轧制过程的轧制压力计算模型,同时给出了带钢上下表面摩擦因数返算方法。最后,为了验证模型的准确性,利用国内某平整机组的设备参数和实际生产过程中的典型规格带钢工艺参数,对比不同润滑条件下本轧制压力模型理论计算值与工程适用的平整轧制压力模型计算值和现场实测数据。结果表明,提出的平整过程中异步轧制轧制压力计算模型能适用于异步轧制情况下的轧制压力计算,与工程适用的平整轧制压力计算模型相比误差减小5%,具有...     

平整轧制压力预测模型比较

针对平整工艺和平整流组成的特点，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：当压下量小于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。     

不锈钢/碳钢复合板平整轧制过程板形翘曲行为

 针对不锈钢/碳钢复合板在平整轧制过程中极易出现不均匀延伸并导致板形翘曲的行为,建立了不锈钢/碳钢复合板平整轧制过程的有限元数值模拟模型,对已实现工业化批量生产的不锈钢/碳钢复合板平整轧制过程的不均匀变形行为及其可能导致的板形翘曲缺陷进行数值模拟研究。在此基础上,对比分析了均质板、非对称不锈钢/碳钢复合板以及对称不锈钢/碳钢/不锈钢复合板平整轧制过程板形的遗传与演变规律,发现仅非对称不锈钢/碳钢复合板在平整轧制过程中极易产生板形翘曲缺陷,同时对比分析了平整和常规轧制对非对称不锈钢/碳钢复合板轧后翘曲缺陷的影响。揭示了不锈钢/碳钢复合板厚向分层特征以及复合板尺寸参数、平整工艺和平整机设备参数等对其板形翘曲缺陷的影响规律,研究表明,对复合板尺寸参数而言,平整过后翘曲高度与厚度比呈正比。对于平整工艺而言,当等张力平整轧制时,平整过后翘曲高度与张力呈正比;当不等张力平整轧制时,前张力的变化对平整过后翘曲缺陷的影响较大;同时平整过后翘曲高度与轧辊和碳钢层表面摩擦因数呈反比。对平整设备参数而言,平整过后翘曲高度与碳钢层表面接触的轧辊辊径、入口侧防皱辊抬起高度以及不锈钢层表面接触轧辊偏向入口侧的距离均呈正比关系。最后,采用轧制试验对数值模拟结果进行了验证,证明了复合板平整轧制模型的准确性。基于上述研究结果,提出了相应的工艺对策,为金属复合板平整轧制过程的板形翘曲控制提供了理论依据。     

工程实用平整轧制压力模型及其自学习技术研究

针对传统的以赫希柯克公式为基础的轧制压力模型不适合于平整轧制的问题,经过大量的现场数据回归与理论分析,充分考虑到不同平整机组的设备工艺特点与实际工况,综合轧制速度、变形抗力、张力、伸长率等平整轧制工艺参数的影响,根据平整轧制过程轧辊与带材交界面处接触弧更具平面性质而非圆柱表面性质的特点,在罗伯茨平整轧制压力模型的基础上,提出了一套工程上实用的平整轧制压力计算模型,同时给出了相应的模型自学习方案,并将其应用到宝钢冷轧薄板厂1220平整机机组的生产实践,95%以上的钢卷轧制压力预报值与实际值的相对误差在10%以内,达到了工程要求,取得了良好的使用效果,具有进一步推广应用的价值.     

莱钢1500mm冷轧带钢平整轧制工艺实践

介绍了莱钢1 500 mm单机架四辊平整机组的设备组成、控制系统以及平整生产模式。通过对平整延伸率自动控制系统(AEC系统)和分段张力控制系统进行分析,在工艺参数的设置、系统控制的优化、生产模式的选择等方面做到有效控制,从而提高了平整延伸率的控制精度35%,确保了平整后产品力学性能与表面质量的稳定性,产量提高了26%。     

攀钢冷轧厂平整机组思制线调整系统优化

本文介绍了攀钢冷轧厂平整机组轧制线调整系统,分析了平整机组轧制线调整系统存在的缺陷和优化改造方案。     

Three-Dimensional Model for Strip Hot Rolling

Steel stripis widely usedin many fields such asautomobile ,building,transportation and householdappliance ,etc·. Withthei mprovement in productiv-ity and automation of strip processing,the require-ments for crown and flatness of strip have been in-creasingly severe ,and“crown free”steel strips arerequired for some special applications such as for au-tomobile parts andtinplate cans .In order toi mprovethe strip quality , an effective three-di mensionalmodel is needful to further study on the…     

轧机辊间压力与压扁之间线性关系的解析研究

通过对现有各种辊间压力与压扁计算理论及方法的分析和进一步的理论推导及有关实验验证,证明辊间弹性接触压扁和接触压之间存在着非常良好的线性关系,计算轧辊接触弹性变形时利用线性关系可获得较高的精度。     

Practice of Improving Roll Deformation Theory in Strip Rolling Process Based on Boundary Integral Equation Method

Precise strip-shape control theory is significant to improve rolled strip quality, and roll flattening theory is a primary part of the strip-shape theory. To improve the accuracy of roll flattening calculation based on semi-infinite body model, a new and more accurate roll flattening model is proposed in this paper, which is derived based on boundary integral equation method. The displacement fields of the finite length semi-infinite body on left and right sides are simulated by using finite element method (FEM) and displacement decay functions on left and right sides are established. Based on the new roll flattening model, a new 4Hi mill deformation model is established and verified by FEM. The new model is compared with Foppl formula and semi-infinite body model in different strip width, roll shifting value and bending force. The results show that the pressure and flattening between rolls calculated by the new model are more precise than other two models, especially near the two roll barrel edges.     

Application of the theory of rolling to rolling in the case of mill vibrations

Knowledge of the reactions of the roll gap according to variable gap geometry, especially of the roll force as a function of vertical displacement of the work rolls, is required to calculate the oscillatory behaviour of the roll stand. The basic equations describing the pressure distribution in the roll gap with variable geometry are formulated using the methods of continuum mechanics. The flattening of the work rolls is taken into account by using Hitchcock's formula. Exemplary calculations show that during vibration the tension between the stands can vanish or the neutral point can surpass the roll gap exit. Both effects may result in tearing the strip at the entry of the affected mill stand.     

Calculating the flattening coefficient between roll gaps at the horizontal deflection of work rolls

The market demand for high-quality cold-rolled strips has increased along with the rapid development of home appliance manufacturing, aviation and other fields. As the existing research has been largely ignored on the horizontal deflection of work rolls, this paper investigates the characteristics of the equipment and the processes of a slender rolling mill, and then proposes a model for calculating the flattening coefficient between roll gaps at the horizontal deflection of work rolls. A typical product of a 550 mill taken from a steel plant is used as an example, and the factors that affect the flattening coefficient between roll gaps, including the difference between the front and rear tension and the diameter of work rolls, are quantitatively analysed. This paper then proposes a forecasting software that can greatly strengthen the plate-shape controlling ability of rolling mills and improve their product quality, thereby the software deserves to be promoted.     

变接触长度支承辊间等接触压力时轧辊变形规律

以某中板厂生产条件和数据为基础,讨论了变接触长度支承辊辊间接触压力相等时的轧辊变形情况.在不同轧制压力前提下,首先计算出轧辊辊身中点处及轧辊与轧件边部相对应点处的变形,然后再绘制出变形沿辊身的分布规律,发现压扁变形比弯曲变形大,同时当轧制压力增大时,轧辊变形随辊身长的变化率亦会增大.     

Compatibility Assessment of Drip Irrigation Laterals

Emitters inserted in drip irrigation laterals cause local head loss, generally estimated as a product of a coefficient and the velocity head. This local head loss coefficient and the emitter discharge curve hydraulic parameters may exhibit considerable variability attributable to the manufacturing process. This paper provides a framework for assessing whether the variability in the hydraulic parameters could lead to significant differences in the performance of rolls of drip irrigation laterals from the same manufacturing batch. A system approach with inlet pressure as input, pressure distribution along the drip lateral and inlet discharge as outputs (or responses), and a drip lateral hydraulic model as the transfer function is explored. Within a Bayesian statistical framework of parameter uncertainty based on the Metropolis algorithm, the hydraulic parameters of pressure-compensating drip lateral rolls from the same manufacturing batch were inferred (calibrated). Overlapping of the space (region) of the hydraulic parameters of different drip laterals give an indication of compatibility (similarity) of the drip laterals. Results indicated that half of the drip lateral rolls tested were strongly compatible, a third were weakly compatible, and the remainder were not compatible with any other. This finding has significant ramifications in the design of drip irrigation lateral networks. Therefore, it is essential to closely examine the hydraulic properties of drip laterals for the design of drip irrigation networks to avoid poor performance of the system.     

卷取机张力建立后助卷辊摆开的自动控制

简要介绍了卷取带钢头部和尾部过程中助卷辊的踏步控制功能所起的作用.针对卷取机张力建立后助卷辊摆开的自动控制进行了详细介绍,助卷辊协助芯轴控制带钢头部建立张力,张力建立之后,助卷辊自动摆开到最大位,保证带卷边部整齐.     

Development of simulation system of strip flatness for hot tandem mill

Using three-dimensional rigid-plastic finite element method base on Lagrange multiplier to analyze the deformation of strip,influence function method to calculate the elastic deflection of rolls and three-dimensionalelastic FEM to analyze the flattening deformation between work roll and strip,a coupled model was established with a iteration way.The effect of various kinds flatness control method such as bending force,rolls shift and cross angle and also various kind of influence factors such as friction ...     

A new way to reduce the edge drop

Two new ways to reduce the edge drop are being investigated both theoretically and in rolling trials. The edge drop control cooling system (EDC cooling) produces a crown shape with the aid of three cooling beams arranged on stand-exit side that, on the one hand, feature a very fine spray pattern distribution in the strip edge area and, on the other hand, are applied with differently tempered cooling medium, allowing the edge drop to be reduced. The EDC rolls are more flexible in the strip edge area than in the remaining part of the barrel. The thus created heavier flattening is, on the one hand, sufficiently large and, on the other hand, also excellently suited by its characteristic property to compensate the edge drop. The effects of both systems were evidenced during comprehensive rolling trials in the first stand of a 2-stand DCR cold tandem mill. For these trials 52 coils of annealed tin plate were used. With the aid of the EDC system, the strip thickness in the immediate strip edge area could be increased by up to 4% of the nominal thickness.