浅析双机架平整机组的张力控制系统

张力控制系统是双机架平整机组稳定运行的关键环节。简要介绍了双机架平整机工艺控制流程和张力控制在轧制过程中的作用,分析了张力的控制方式、保持恒张力的方法。该套张力控制系统在双机架平整机组运行稳定,实际应用效果较好。     

双机架在线平整机组过焊缝技术应用

双机架平整机组二次冷轧过程中,极易发生断带情况。分析了首钢京唐公司在线双机架平整机组过焊缝过程中月牙区域断带的原因,一是局部浪形过大,导致部分形成应力集中;二是在线DCR平整过程中张力较大,局部应力集中,导致带钢屈服失稳,拉断带钢。通过调整辊系的水平度和垂直度,制定无带钢标定和轧制力偏差异常的临时控制措施;同时开发过焊缝自动降低张力程序,将机组过焊缝平整机前后张力降低20%,机组的断带率从2次/月降至0次/月。     

酸洗浪形卷在冷轧平整机的返修实践

介绍了邯钢公司冷轧厂利用冷轧平整机挽救酸洗浪板的生产情况。对比了干、湿平整模式对酸洗板表面质量的影响,分析了平整后酸洗板力学性能的变化规律,并对比了恒轧制力与恒延伸率平整模式对板形的影响。最终采用恒轧制力、湿平整模式对酸洗浪板进行平整挽救,返修酸洗浪形卷的一级品率由20%逐步提高到50%,大大减少了因浪形导致的酸洗降级品。     

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.     

武钢冷轧厂平整机速度控制系统

介绍武钢冷轧厂平整机的速度控制系统。叙述Ｓ型曲线在平整机速度控制中的应用及实现方法,平整过程中的自动制动控制原理及实现方法,卷以机速度控制与张力控制的平滑切换,控制系统的构成。单、双机架平整机改造后,年产量增加１０万ｔ,产品质量提高,故障率大大降低。     

冷轧极薄规格带钢羽痕缺陷生成机理与控制

针对双机架平整机生产极薄规格带钢时表面出现的羽痕缺陷生成机理进行了分析。通过研究发现,羽痕生成是由于极薄规格带钢在宽度方向上由轧制力和张力共同作用下出现不均匀变形,该变形产生的分界线在平整过程中出现了不均匀延伸;而在平整过程中由于弯辊和窜辊的预设定参数不合理、单位张力设定偏低、平整过程中弯辊力与轧制力不匹配等因素导致带钢局部延伸偏大,形成了明显的浪形,此浪形若经过平整机辊缝碾压则生成羽痕缺陷。通过将平整机设定张力提高30%、调整板形曲线为1~8 IU的大边浪、依照带钢厚度调整平整机板形预设定参数以及开发轧制力弯辊力跟随控制模型等措施,极薄规格带钢羽痕缺陷带出品由 206降至51 t/月,基板表面质量满足了国内外多家高端用户的要求。     

硬质薄规格镀锡板平整轧制变形行为与辊形技术

以某厂镀锡板连退机组双机架HCM平整机为研究对象,理论分析结合有限元仿真和现场实验,对硬质薄规格镀锡板的平整轧制变形行为进行了研究,揭示了硬质薄规格镀锡板平整时轧制力偏大、实际延伸率达不到设定目标延伸率以及实物板形质量较差的原因,确定了相应的解决问题的技术思路.在此基础上,运用基于有限元仿真的辊形设计方法和软件,研制了新的中间辊端部辊形.生产应用结果表明,该中间辊端部辊形能够有效地减轻压靠、稳定实现设定的目标延伸率且实际平整轧制力降低10%～20%,而且还可以根据需要在正常平整轧制力下使实际延伸率增加0.1%～0.2%.     

一种双机架六辊 UCM 平整兼二次冷轧机组

针对传统双机架平整兼二次冷轧机的系列问题,开发了一套双机架六辊UCM平整兼二次冷轧机组。该机组相对传统机型增加中间辊窜辊、中间辊弯辊等板形调节手段,更好地改善板形;该机型采用1＃机架乳化液直喷辊缝润滑、1＃机架配置双辊系,大幅度降低轧制力、提高轧制稳定性;该机型开发乳化液阻隔及防结露装置、辊缝吸尘装置及支承辊擦拭器等装置,降低板面乳化液残留、消除金属粉尘,提高产品质量,减少环境污染。     

一种新型平整机——二辊式普通和异步两用平整机的设想

本文分析了二辊式普通和异步两用平整机所具有的特点,认为是一种既能以恒延伸平整薄带钢,又能以良好板形平整较厚带钢的最佳平整机,也是异步轧制新工艺在大型轧机上的合理应用,是鞍钢冷轧厂以平整较薄和较厚带钢为主的理想机型。     

连退平整机横向辊印研究与控制

针对冷轧连退线平整机换辊后带钢表面存在横向辊印的问题,通过一系列试验和分析,确定平整机在换辊闭合机架过程中工作辊辊面损伤导致带钢表面横向辊印缺陷的发生。通过对平整机轧制力控制系统优化改进,将传统的恒参数PID轧制力控制优化为针对不同工况的自适应调节参数PID轧制力控制,减小了平整机机架闭合过程中工作辊与带钢之间的冲击,避免了平整机工作辊辊面损伤,连退产品的横向辊印检测合格率由86.7%提高到99%,基本消除了横向辊印缺陷,保证了带钢的表面质量。     

宝钢1550连续退火机组平整机延伸率控制技术

宝钢 15 5 0CAL平整机延伸率反馈采用KC5A智能模块 ,KC5A模块的延伸率累计偏差输出具有实时性 ,使延伸率偏差控制具备平滑连续性 ;同时采用平整机前后张力独立闭环控制、轧制力闭环控制延伸率以及加减速时轧制力前馈控制等先进技术。系统投入运行以来稳定性好、控制精度高 ,经平整后带钢具有机械性能好、平直度高、能有效调节带钢表面粗糙度等优点。     

具有伸长率分配计算功能的轧制力预报智能模型研究

针对双机架平整机的特性,以基态弯辊力下带材出口板形最好为准则,提出具有双机架平整机伸长率分配系数计算功能的轧制力模型;在此基础上,为了改善传统轧制力模型的预报精度,提出了先通过神经网络利用在线测得的实际数据预测变形抗力和摩擦因数,再与轧制力机理模型自学习过程相结合的轧制力预报新方法;并将其应用于宝钢1220双机架平整机的生产实践,结果表明此模型可以高精度地预报轧制压力.     

Optimum Temper Rolling Degree: Pre‐Set and Influencing Effects of Bending Deformations

The present article describes a research project concerning the influence of bending deformations on strip mechanical properties imparted by temper rolling and a strategy for mill pre‐set to achieve the selected temper rolling degree in as short a time as possible. Research results show that, during strip temper rolling, rolls involved in the process, for example deflector rolls and anti‐sticking rolls, introduce plastic bending deformations into the strip which can amount to more than 30% of the temper rolling reduction, depending on the effective bending radii. Bending tests involving strips made of low‐carbon steel in a tension roller system with an integrated bending unit demonstrate that bending deformations influence the mechanical properties of the strip in a manner similar to the temper rolling process itself. It appears necessary to take account of the bending effects when selecting the optimum temper rolling degree. The most accurate roll force pre‐calculation possible and its application at the mill stand are of major importance for pre‐setting the required temper rolling degree. Existing analytical methods have been unable to yield the necessary calculation accuracy. Combination of an optimised analytical approach with a data‐based model to create a hybrid model has led to significant improvements. The accuracy achieved in the pre‐calculation of the required roll force has helped to improve mill pre‐set of the investigated temper mill and to reduce strip head‐end scrap on average by around 6 m per strip. Based on the annual outputs stated by the plant operator, this makes it possible to achieve a cost saving of more than 200,000 € per year.     

热轧薄规格带钢平整过程板形控制技术

为了提高热轧薄规格带钢平整的板形质量,在平整机上采用了新的辊形配置。在支撑辊上采用变接触式 支撑辊辊形,在工作辊上采用六次方多项式正凸度辊形。变接触支撑辊辊形可以降低轧辊挠曲变形和边部应力的 集中,增大弯辊力的调控功效。采用正凸度工作辊辊形,可以弥补平整机的磨损辊形,延长平整轧制计划单位的长 度。此辊形配置在首钢迁钢热轧平整机上应用,保证了平整改善薄规格带钢板形质量,延长了平整轧制计划的长度。     

Effect of Temper Rolling on Tensile Properties of Low-Si Al-Killed Sheet Steel

The tensile properties of steel after temper rolling are affected by the reduction; low-Si Al-killed sheet steel was taken to study the effect of temper rolling on the tensile properties. The results indicate that the yield strength first decreases with the increase of reduction, and then increases. The relationship between the yield strength and the reduction can be expressed using quadratic function. The tensile strength increases with the increase of the reduction, while the total elongation decreases with the increase of the reduction, and the relationship between them and the reduction can be expressed using power function. Under the same condition, the results also indicate that the yield strength and tensile strength of steels across the rolling direction are all larger than those along the rolling direction; there is no obvious distinction between the total elongation along the rolling direction and that across the rolling direction.     

Effect of Temper Rolling on Tensile Properties of Low-Si AI-Killed Sheet Steel

The tensile properties of steel after temper rolling are affected by the reduction;low-Si Al-killed sheet steel was taken to study the effect of temper rolling on the tensile properties.The results indicate that the yield strength first decreases with the increase of reduction,and then increases.The relationship between the yield strength and the reduction can be expressed using quadratic function.The tensile strength increases with the increase of the reduction,while the total elongation decreases with the increase of the reduction,and the relationship between them and the reduction can be expressed using power function.Under the same condition,the results also indicate that the yield strength and tensile strength of steels across the rolling direction are all larger than those along the rolling direction; there is no obvious distinction between the total elongation along the rolling direction and that across the rolling direction.     

2030冷轧平整机轧制力模型研究

在研究冷轧平整控制模型的过程中发现 ,带钢延伸率变化与其轧制力密切相关。L2级计算机的轧制力预设值对保持延伸率稳定是一个主要因素。通过研究找出了用轧制力控制延伸率的规律。     

Nonlinear Finite Element Analysis of Thin Strip Temper Rolling Process

 To reveal the basic deformation mechanisms under the conditions of high friction, small reduction, and long contact length in thin strip temper rolling process, an elastoplastic finite element analysis of plane strain upsetting was made based on the FEM software Marc. The results indicated that a near flat ‘zero reduction’ region was present in the center of the contact arc. The simulation results about the effect of rolling parameters on the central flat region showed that any change of increasing the rolling force could result in or enlarge the central flat region in the deformation zone. Stress distribution results illustrated that the metal was in triaxial compression state. Although the maximum and minimum principal stresses were all much larger than the yield stress of the strip, the equivalent stress became lower than that, and no further plastic strain, even a small elastic spring back occurred in the central flat region. That was the problem of ‘hydrostatic pressure’ in thin strip temper rolling.     

平整轧制过程中工作辊粗糙度衰减模型

 针对以往平整工序工作辊表面粗糙度衰减模型仅仅考虑轧辊材质与轧制公里数影响，而忽略所平整带钢的特性以及轧制压力等工艺参数作用，造成辊面实际粗糙度预报误差较大以致影响成品带钢表面粗糙度的控制精度问题，充分结合平整轧制过程的设备与工艺特点，通过大量的理论研究与现场试验，在从微观层面分析了平整轧制过程中工作辊表面粗糙度衰减机理的基础上，不但考虑到工作辊表面硬度、表面原始粗糙度的影响，而且考虑到平整轧制过程中的单位轧制压力及单位摩擦应力的作用，建立了一套适合于平整轧制的工作辊表面粗糙度衰减模型，编制出了相应的工作辊表面粗糙度预报软件，并将其应用到某1 420平整机组的生产实践，取得了良好的使用效果，提高了成品带钢表面粗糙度的控制精度，为机组创造了较大的效益，具有进一步推广应用的价值。     

平整工艺对冷轧780MPa级双相钢力学性能的影响

采用不同的平整工艺对连续退火780 MPa级别的冷轧双相钢进行平整试验,研究了平整伸长率对连续退火780 MPa级别双相钢力学性能的影响,并建立了平整伸长率与780 MPa级别双相钢力学性能的函数关系模型。研究表明：随着平整伸长率的提高,780 MPa级别双相钢的屈服强度提高,抗拉强度保持不变,同时均匀伸长率和总伸长率均有所下降。