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…     

涟钢CSP热轧平整机辊形优化技术的研究

涟钢1800CSP热轧平整机在生产中存在一些板形缺陷,用户反馈板形质量异议在5%以上。为了提高该机组的板形控制水平,减轻工作辊“W”形不均匀磨损对板形的影响,并提高单辊过钢量,针对热轧平整机工艺特点,本文以工作辊和支持辊间接触压力分布均匀化和前张力分布均匀化为目标,优化设计了新的工作辊及支持辊辊形。理论计算和现场应用表明,优化后新辊形使辊间接触压力分布趋于均匀,平整机工作辊“W”形磨损得到缓解,单辊过钢量与板形质量均显著提高。     

宽带钢热连轧机组均压支承辊辊形开发与应用

 CVC工作辊辊形自发明以来在全球150多条热连轧生产线上得到应用,以控制带钢的板形。实际应用中,与CVC工作辊配对使用的支承辊无论采用平辊还是CVC辊形均存在非均匀磨损甚至轧辊剥落失效的问题,主要原因是CVC支承辊辊形和平支承辊与CVC工作辊配置时存在接触压力集中。为了解决此问题,设计并应用了一种均压支承辊辊形与CVC工作辊配置使用。此辊形是变接触支承辊辊形（VCR）与CVC支承辊辊形的组合,具有变接触辊形的优点,同时又能更好地与CVC工作辊配置使用。均压支承辊辊形应用后,改善了CVC工作辊与支承辊辊间接触状态,解决了轧辊剥落问题,并改善了带钢凸度质量。     

Roll Wear Evaluation of HSS,HiCr and IC Work Rolls in Hot Strip Mill

While it is acknowledged that roll wear is one of the most challenges to hot strip mills (HSM), very few studies which detail an exact prediction model have been published. The aim of this work is to evaluate and compare two prediction models with measured roll wear. The first prediction model, model 1, developed for a plate mill, was modified to use in strip rolling process. The second prediction model, model 2, is a simplified on‐line model. Data of two hot strip mills were used to investigate the influence of different rolling schedules. The rolls and strip properties were described and the rolling conditions were detailed. The influence of hot rolling factors, such as strip strength, roll grades, rolling temperature, rolling force, reduction and contact length, were also studied. When rolling with different work roll materials and strip grades, the modified prediction model has better prediction accuracy than the simplified model. The accuracy of both models becomes better at higher roll wear > 150 μm. HSS work rolls were confirmed to exhibit improvement of roll wear in comparison with HiCr rolls, the wear resistance was 3 to 4 times better. The influence of strip grade on roll wear was shown to be significant, with higher accuracy of the regression statistics for rolling with similar strip grades and lower regressed accuracy for rolling with mixed strip grades. The roll wear was evaluated at the centre of the barrel.     

CSP末机架支持辊辊形研究

针对CSP热连轧F7机架支持辊辊形高、窜辊分布不合理、轧制薄规格时出口板形易出现中间浪、下机磨损不均匀、磨损严重且CVC趋势比较明显等问题,提出与CSP热连轧工作辊辊形相匹配的支持辊新辊形VCR+,采用二维变厚度有限元模型对新辊形的板形控制性能进行了分析,并且在F7机架上进行工业试验。研究结果表明,新辊形VCR+使用后工作辊窜辊分布更加合理,使得出口板形中间浪问题有了明显的改善;轧辊的自保持性能有了显著的提高,从而延长了轧制公里数,降低了生产成本。     

辊形配置对辊间接触压力与板形调控影响分析

为系统分析不同辊形配置下辊间接触压力分布形式与板形调控特性,以某1 800 mm热轧生产线使用的2种典型辊形配置为研究对象,建立对应的辊系有限元模型,计算不同带钢规格与调控手段下辊间接触压力分布形式,分析得出常规凸度支撑辊对应的辊间接触压力分布形式与CVC工作辊辊形呈现出明显的对应性,且压力分布形式受轧制规格与调控手段的影响明显小于CVC支撑辊。利用接触压力峰值和不均匀度表述辊间接触压力分布特征,将不同规格与调控手段对辊间接触压力分布特征的影响进行量化处理,得到更为具体的不同参量在整个变化范围内对分布特征的整体影响趋势。同时还对2种辊形配置下不同辊间接触压力对轧机板形调控特性影响进行分析,得出CVC支撑辊对应辊形配置的弯辊力与窜辊位置在板形调控能力上均强于常规凸度支撑辊辊形配置,而不同辊形配置对辊缝形状的影响表现出较为明显的差异,引入辊间接触压力边中比得到调控特性与辊间接触压力之间的具体关系,并结合现场的实际生产数据对仿真分析结果进行验证,研究结果可为现场辊形配置与板形调控提供较好的理论基础和生产指导。     

辊形配置对辊间接触压力与板形调控影响分析

为系统分析不同辊形配置下辊间接触压力分布形式与板形调控特性,以某1 800 mm热轧生产线使用的2种典型辊形配置为研究对象,建立对应的辊系有限元模型,计算不同带钢规格与调控手段下辊间接触压力分布形式,分析得出常规凸度支撑辊对应的辊间接触压力分布形式与CVC工作辊辊形呈现出明显的对应性,且压力分布形式受轧制规格与调控手段的影响明显小于CVC支撑辊。利用接触压力峰值和不均匀度表述辊间接触压力分布特征,将不同规格与调控手段对辊间接触压力分布特征的影响进行量化处理,得到更为具体的不同参量在整个变化范围内对分布特征的整体影响趋势。同时还对2种辊形配置下不同辊间接触压力对轧机板形调控特性影响进行分析,得出CVC支撑辊对应辊形配置的弯辊力与窜辊位置在板形调控能力上均强于常规凸度支撑辊辊形配置,而不同辊形配置对辊缝形状的影响表现出较为明显的差异,引入辊间接触压力边中比得到调控特性与辊间接触压力之间的具体关系,并结合现场的实际生产数据对仿真分析结果进行验证,研究结果可为现场辊形配置与板形调控提供较好的理论基础和生产指导。     

1 250 mm热连轧工作辊磨损控制策略

 国内大量的1 250 mm热轧机精轧机组普遍使用带有负凸度的凹形工作辊,由于轧机辊形配置及轧制工艺特点,工作辊出现严重“猫耳”型磨损,造成轧制带钢断面出现局部高点现象。为改善1 250 mm热连轧工作辊的磨损,提升带钢板形质量,提出了一种适用于1 250 mm热连轧工作辊磨损的控制策略,在保证板带稳定轧制的同时,通过轧辊辊形和工作辊窜辊策略优化来控制工作辊的磨损。本策略已应用于德龙钢铁有限公司轧钢厂,工业试验表明,该策略可减小工作辊磨损量,使轧辊磨损更加均匀,增加弯辊力调控能力,并使工作辊单位周期轧制带钢长度延长40%,对1 250 mm热连轧产线工作辊磨损控制具有研究价值和推广前景。     

板宽对4辊CVC热轧机板形控制能力的影响

采用流面条元法分析带材的三维塑性变形，影响系数法分析辊系的弹性变形，并将二者耦合，建立了4辊轧机板形和板凸度的分析计算模型，并针对板宽对4辊CVC热带钢轧机板形控制能力的影响进行了仿真研究。仿真结果表明，随着板宽的增加，出口板凸度先增大后减小，辊缝变得越来越平缓；单位宽度辊间压力增大，且沿横向的变化比较均匀；板带的宽展减小。对热带钢轧制，乃至厚板轧制具有重要的意义。     

Analysis of Roll Gap Pressure in Sendzimir Mill by FEM

The acting force on the roll system of Sendzimir mill was analyzed using 3D FEM.The roll gap pressure distribution and the acting force between rolls S and O,rolls O and I,rolls O and J,rolls I and A,rolls I and B,as well as rolls J and B were analyzed.The results showed that the roll gap pressure mainly affected the roll surface layer,50 mm for backup roll;the roll gap pressure distribution is of double peaks among the work roll,the 1st intermediate roll（IMR）,and the 2nd IMR;the maximum value of the roll gap pressure between the backup roll and the second IMR appears on the edge of the barrel of rolls;the component force presents the in-para-curve distribution.These are important for reducing the wear of rolls and the break of the backup roll and guiding for production.     

四辊CVC冷轧机辊间压力影响因素分析

CVC轧机辊间接触压力分布不均,辊间压力峰值易引起严重的支撑辊不均匀磨损,甚至造成轧辊的剥落。采用影响函数法,分析了轧件宽度、工作辊横移位置、弯辊力以及支撑辊凸度对辊间压力分布的影响;研究了在应力集中最严重的横移位置时,支撑辊端部采用圆弧形倒角和抛物线形倒角时,倒角参数变化对辊间压力分布的影响规律。结果表明:CVC轧机辊间压力成S形分布,在轧辊右端存在较大的应力集中;轧件越宽,应力集中越严重;横移位置为负向最大时,辊间应力集中最严重;增加支撑辊凸度能减小辊间接触压力的峰值,但是对辊间压力分布的改善不明显;弯辊力对辊间压力有较大的影响;使用合适的抛物线形倒角和圆弧形倒角均能很好的减小辊间接触压力的峰值,并使辊间压力分布更均匀。研究结果可为CVC轧机支撑辊辊形设计提供理论依据。     

FEM Analysis of Rolling Pressure Along Strip Width in Cold Rolling Process

 Using 3 D elastic plastic FEM, the cold strip rolling process in a 4 high mill was simulated. The elastic deformation of rolls, the plastic deformation of the strip, and the pressure between the work roll and the backup roll were taken into account. The distribution of rolling pressure along the strip width was obtained. Based on the simulation results, the peak value of rolling pressure and the location of the peak were analyzed under different rolling conditions. The effects of the roll bending force and the strip width on the distribution of rolling pressure along the width direction were determined.     

New Method for Evaluating Thermal Wear of Rolls in Rolling Process

A new method was developed by a thermal wear machine to evaluate the thermal wear of roils in steel rolling process. The steel strip and rolls were simulated by upper and lower heating disks. The upper heating disk could he kept at a temperature of over 900 ℃ by induction heating. The pressure between the disks as high as 323.2 MPa could be achieved and the slipping rate could be 12. 7 %. The thermal wear of high speed steel （HSS） roll material, the wear rate of the HSS roll, and the SEM morphology of a worn HSS roll surface were investigated. This method was useful and could be employed to simulate friction and wear between strip and roll during the strip rolling process.     

热连轧机支承辊辊型曲线多目标优化设计研究

以850 mm四辊热连轧机组为研究对象,建立了轧辊辊间接触压力和板形计算模型,以均匀辊间接触压力分布和带钢板形良好为目标,对热连轧机精轧机组支承辊辊型曲线进行了多目标优化设计。理论计算表明,优化后的支承辊辊型曲线均匀了辊间接触压力分布,降低了辊端接触压力峰值,同时能够提高弯辊力对板形的控制效果。工业生产试验后正式推广使用,支承辊掉肩和掉肉现象得到了有效遏制,带钢板形良好。     

无取向电工钢热轧楔形问题分析与控制

电工钢板形质量要求严苛,无取向电工钢热轧生产中存在的较大楔形,给冷轧等后工序生产带来了严重的困难,成为制约电工钢产品质量的重要因素。首先通过中间坯断面形状测量统计、红外热像观测和轧辊磨损测量等方法对电工钢热轧楔形问题进行分析,然后通过基于电工钢实际材料模型的有限元仿真分析来料楔形、轧辊不均匀磨损和单相区以及两相区温度不均匀分布等因素对轧后带钢楔形的影响。分析结果发现,来料楔形在后续对称轧制条件下可减小但很难完全消除;工作辊磨损倾斜对楔形的影响比支撑辊更大;横向温度倾斜对楔形的影响最大,较小的横向温差即引发巨大楔形,两相区轧制时横向温度倾斜引发的楔形比单相区大。基于以上研究,针对性地提出无取向电工钢楔形控制措施,并分析控制效果。     

热轧薄带平整机支撑辊辊型优化的研究与应用

某热轧薄带平整机轧辊长度为1 800 mm,带钢宽度为1 320 mm,两者相差太大,造成工作辊与支撑辊间有害接触区长度过大,在轧辊自身挠度作用下,辊间应力峰值集中于带钢边部位置.随轧制公里数延长,工作辊边部磨损加剧,不利于后期板形控制,同时会缩短轧辊使用寿命.针对热轧薄带平整机工作辊磨损不均匀问题,设计优化支撑辊辊型...     

工作辊驱动UCM轧机支撑辊配辊策略

 轧辊是钢铁企业的重要消耗品,降低轧辊消耗是当前钢铁企业降本增效的要求之一。硅钢断带和粘钢容易引起支撑辊辊面掉肉及裂纹,造成支撑辊磨削差异大、配辊难。合理设计配辊辊径差可方便轧辊管理,减小支撑辊下机后不必要的磨削量,显著降低辊耗成本。但是支撑辊是影响轧制稳定性的重要部件,为此从动力学原理分析了工作辊驱动的UCM轧机上下支撑辊辊径差异对加减速过程驱动力矩的影响,根据弹性力学原理分析了上下支撑辊和中间辊压扁量差异对带钢厚度设定和控制精度的影响。生产应用最新配辊方案表明,合理的配辊策略不仅不会影响生产,而且方便轧辊管理,降低辊耗成本。     

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。     

宽带钢热连轧支承辊磨损模型研究

在实测热连轧支承辊磨损辊形的基础上,采用分割法,沿支持辊轴向把辊身分成均匀的等分,建立了热连轧支承辊磨损辊形数学模型,该模型根据带钢的轧制工艺参数可以及时地计算出支承辊在线磨损辊形.从与现场收集的支承辊磨损辊形数据的对比中可以得出,该模型对支承辊的预报磨损辊形与实际磨损辊形很接近,具有较高的实用性.     

热轧薄带轧制稳定性影响因素分析

结合热轧薄带生产的技术特点,对其轧制稳定性影响因素进行了分析,提出了应对措施:采取合理安排轧制计划、提高加热温度、减少除鳞道次、严格控制辊形、提高轧机各支承辊和工作辊装配精度等,可以提高热轧薄带轧制的稳定性。