厚度小于2．5mm热轧焊管坯生产

采用“三辊异径”工艺对热轧窄带钢轧机进行了改造，即在原二辊之间增加一被动小工作辊，轧件在小工作辊与原下工作辊之间通过，轧制压力可下降４９％～６２％，所轧带钢可减薄，且平直度和表面质量均很好。简介了该工艺的特点和生产情况以及经济效益。     

四辊板带轧机辊颈载荷分布及板形影响因素分析

板形是板带材产品的重要质量指标之一。辊系弹性变形是影响板形的主要因素,轧机辊颈载荷分布直接影响轧机的辊系弹性变形,因此精确分析辊颈载荷分布对板形控制和轴承使用有着重要的意义。针对实验室四辊可逆冷轧机,采用ANSYS/LS-DYNA有限元软件,基于显式动力学建立了耦合支撑辊轴承、轧辊和轧件的三维实体模型,分析了板宽、摩擦因数、张力和压下量等因素对支撑辊辊径载荷分布和板凸度的影响,对四辊板带轧机板形控制和轴承使用提供了理论支持。     

Development of satellite mill and trial rolling of profiled metal strip

A new type of compact continuous mill called the “Satellite mill” has been developed to produce profiled metal strip from flat strip. This mill consists of one large-diameter driven roll (central roll) and five smaller rolls (satellite rolls) arranged along the periphery of the central roll. A strip is continuously rolled at five gaps between the central roll and the satellite rolls. All rolls are driven at an equal roll peripheral speed to promote transverse metal flow or lateral spread. Guide shoes are provided between the adjacent satellite rolls and are supported with two adjacent satellite rolls. They prevent a strip from bulging or buckling. A test mill was constructed, and rolling experiments have been performed on the production of T-shaped or U-shaped profiled aluminum strip. The deformation- load characteristics were investigated and compared with those of conventional rolling. As a result, in the satellite mill rolling operation, elongation was suppressed. Lateral spread was enhanced, and the profile of the product cross section was significantly improved. Consequently, the new rolling process was found to be forming of profiled metal strip.     

Causes of chatter in a hot strip mill: Observations, qualitative analyses and mathematical modelling

Severe vibrations, known as chatter, occur often in both hot and cold rolling of steel. A recent chatter outbreak at the second stand of hot strip mill in Hastings, Australia, prompted an investigation into the causes of chatter by a literature review, the development and deployment of mathematical models, and a rigorous analysis of plant observations. The investigation suggests that the frictional conditions in the roll gap are the principal cause of chatter in this mill, though residual chatter marks on work rolls can occasionally cause it. The frictional conditions appear to be associated with the thickness and properties of oxide formed on rolls.     

六辊铝板带冷轧机轧辊倒角仿真分析及工艺优化

辊间压痕是制约六辊铝板带冷轧机实现中间辊抽动功能从而达到改善板形目的的一大障碍。在现场考察的基础上,基于Abaqus有限元软件对六辊铝板带冷轧机进行了辊系受力仿真,得到了辊间受力的情况,分析并验证了辊间压痕的成因是由轧辊倒角设计不合理或磨辊时处理不当,没有把倒圆角倒到规定的标准所造成,并由此提出了对轧辊倒角设计的改进方案并对倒角改进后的辊系受力进行了有限元仿真。结果表明,采用所提出的倒角改进方案能够大幅度减轻辊间压痕,从而对充分发挥六辊轧机的板形控制能力,对改善板形具有重要的意义。     

四辊轧机轧辊弹性变形解析模块的开发

采用影响函数方法开发了四辊轧机轧辊弹性变形解析模块，完善了辊间压扁和工作辊压扁影响函数计算模型，克服了轧辊压扁影响函数计算过程浮点数被零除的缺陷，提出了平滑指数和收敛指标取值的处理方法，有效地解决了四辊轧机辊系弹性变形计算精度及收敛问题。该模块适应于普通四辊轧机、PC轧机和CVC轧机轧辊弹性变形计算，为热轧带钢板形控制提供了解析工具。     

Coupling solved roll contact pressure transverse distribution of HC strip mill

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Rolling of T-shaped profiled strip by the satellite mill

A new type of compact mill called a “satellite mill” is used for producing T-shaped profiled strip from flat strip. The mill comprises one large-diameter flat roll (central roll) and five smaller-diameter caliber rolls (satellite rolls) arranged along the periphery of the central roll. The flat strip is continuously passed through the five gaps between the central roll and the satellite rolls and formed into a T shape. All rolls are driven at an equal peripheral speed to restrain elongation of strip and to promote transversal metal flow. A guide shoe is provided between each two adjacent satellite rolls to prevent the strip from bulging out or buckling. Using aluminum as a model material, some rolling experiments were performed on the mill. T-shaped profiled strips with a thickness ratio (thickness of thick part per thickness of thin part) as high as three were rolled successfully. When deformation and force characteristics were investigated, it was found that, in comparison to a conventional multipass caliber rolling, the elongation of the strip is suppressed and the filling ability is much improved.     

提高热轧带钢辊缝模型精度的措施

辊缝的设定精度与轧机弹跳、辊缝零点漂移和系统误差等因素有关。本文将轧机弹跳分为两部分:辊系的弹性变形和轧机牌坊及其他部分的弹性变形,采用在线解析模型计算受轧制条件变化影响很大的辊系变形量,提高了轧机弹跳的计算精度;利用二维有限差分模型周期计算轧辊的温度场并确定其热膨胀量,可主动补偿其所引起的辊缝零点漂移;通过优化换辊后自学习初始值,可改善辊缝零点修正的效果。改进后的辊缝设定模型应用结果表明,对于3.0～4.5mm厚度规格,95%以上带钢的头部厚度控制偏差小于±0.075mm。     

四辊轧机辊系间的轴向摩擦力对辊系轴承寿命的影响

四辊轧机工作辊轴承和支承辊止推轴承失效的主要原因是它们在工作中所受的轴向载荷过大。工作辊与支承辊轴线的不平行引起其接触面的轴向相对滑动 ,由此产生轴向滑动摩擦力 ,使轧辊轴承最终失效。通过对辊系的分析 ,给出了解决该问题的新的设计思路 ,对新轧机的设计和旧轧机的改造具有指导意义     

Analysis of rolls deflection of Sendzimir mill by 3D FEM

The deflection of rolls of Sendzimir mill with double AS-U-Roll was simulated by finite element method（FEM）. The influences of rolling pressure, strip width and rolls-assignment on rolls deflection were analyzed. The results show that the work roll deflection increases with the increase of rolling pressure and the reduction of work roll radius, but the rigid displacement of work roll slightly changes; the work roll end might appear negative displacement for the narrow strip width and high rolling pressure that might cause the contact of work rolls. The research results are significant for guiding production and theoretical analysis of the rolls system of Sendzimir mill.     

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借助非线性有限元软件Marc,采用弹塑性有限元方法对十八辊轧机辊系进行了模拟,计算模型对辊系的弹性变形与带钢的弹塑性变形按照接触问题进行耦合分析。利用此模型,得出了轧制力对辊系弯曲变形的影响以及辊系弯曲变形沿轧件宽度方向的分布,并分析了轧机工作辊的不同方向弯曲变形情况,由对计算结果的分析可以为该轧机的辊系设计提供理论依据。     

辊面氧化膜局部保留及其对粗轧板形的影响探讨

为改善粗轧R₂新辊上机1万t以内的板形游动和打滑问题,研究了3种不同形式辊面氧化膜局部保留的工作辊对粗轧板形的影响规律。通过分段函数的方法,磨削出3种不同形式的局部氧化膜保留的粗轧工作辊,分别为：上下辊均为半磨削,保留中间氧化膜;上辊为半磨削,下辊为全磨削,上辊保留中间氧化膜;上下辊均保留两肋氧化膜。对比了3种不同形式局部氧化膜保留的工作辊与全磨削工作辊轧制对应的带钢镰刀弯精度。试验结果表明：这3种粗轧工作辊氧化膜局部保留的方式,均可有效控制新工作辊上机初期的板形游动问题,与全磨削工作辊相比,这3种氧化膜局部保留方法可使粗轧板坯镰刀弯控制精度从33%提升至45%。通过对每次下线的工作辊上下对调,再仅将上辊保留中间氧化膜,下辊为全磨削,或者将上下辊均为半磨削和上下辊均保留肋氧化膜的工作辊交替使用,均可实现每套工作辊都有局部氧化膜保留,同时确保轧辊使用安全,有效控制粗轧工作辊上机初期带钢的板形游动问题并提高镰刀弯精度。     

热轧来料楔形对冷连轧机组轧制状态的影响

针对某1420mm冷连轧机组生产中出现的轧制状态不稳定和板形异常问题,通过测量轧辊磨损与机组来料板廓,确定了机组轧制状态的影响因素———热轧来料楔形,并利用有限元软件求解了承载辊缝形状的变化,定量计算了不同凸度支撑辊的辊系对楔形来料的抵抗能力。研究结果对异常来料的工艺问题具有指导意义。     

铸造复合轧辊的几种新方法

高速钢用作轧辊材料使冷、热带钢工作辊寿命得到大幅度提高,但是用常规生产方法包括离心铸造法很难生产出高速钢复合轧辊。介绍了几种新的复合轧辊的生产方法,成功地生产出外层与心轴良好结合的高速钢复合轧辊,其中一些方法可方便地复合各种材料     

四辊轧机轴向力研究

四辊轧机工作辊轴承及支承辊止推轴承失效的主要原因是轴向力过大.辊系各轴线不平行引起辊子间有轴向相对运动的趋势,在轧制压力作用下该轴向相对运动趋势使辊子间产生轴向静摩擦力,这就是产生轴向力的主要原因.通过调整机架窗口衬板和轧辊轴承座衬板,保持辊系各轴线的平行度,可显著降低轴向力,理论分析和实验结果一致.     

两自由度轧机辊系参激刚度非线性振动特性研究

考虑轧机辊系间的参激刚度以及轧制过程中辊系受到的动态轧制力,建立了两自由度轧机辊系参激刚度振动模型。运用多尺度法求解给出了系统1/2亚谐共振和内共振的幅频方程,以某冷轧机实际轧制参数为例,通过数值仿真得到结构阻尼、非线性刚度以及参激刚度等工艺参数变化下系统的幅频响应特性。并采用奇异性理论分析了1/2亚谐共振的静态分岔特性,同时分析了内共振情形下3组不同的转迁集以及相应的分岔拓扑结构图, 得到了轧机稳定与不稳定振动的工艺参数区域。最后研究了工作辊、支撑辊随参激刚度变化的分岔混沌动力学行为,且用最大Lyapunov指数、相轨图以及Poincare截面对其加以验证,发现带材表面出现振纹或振痕的原因是系统在周期运动、倍周期运动与混沌运动多种运动形式间相互转换造成的。因此适当选取系统参数可有效减弱轧机系统的振动,这为消除和抑制轧机振动提供了理论依据。     

用原始辊型法改善热带板形的工艺研究

采用本城恒模型计算了太原钢铁（集团）有限公司1549mm热连轧机精轧机组工作辊的弹性变形，并用二维模型计算了其热凸度。在此基础上确定了精轧机组工作辊宜采用的原始辊型。生产实践表明，该辊型能孵显改善热轧带钢的板形质量。     

提高PC热连轧机支撑辊寿命的优化曲线研究

为解决ＰＣ热带钢连轧机辊间接触载荷不均易造成支撑辊辊面提前损坏的问题,对支撑辊肩部辊形进行了优化设计。经试验验证,采用幂函数的辊形优化曲线可提高支撑辊使用寿命,并有利于板凸度和板形控制。     

本钢冷轧厂平整机组的技术改造

针对平整机组生产率低、稳定性差、功能不完备等问题,对平整机进行了技术改造,增设了一对S辊,保证了稳定的张力轧制;增设了带钢跟踪系统,能够自动测量钢卷直径和宽度;增设了轧辊清扫装置,提高了带钢表面质量。