Tailored Profiles Made of Tailor Rolled Strips by Roll Forming – Part 1 of 2

To fully exploit the potential of sheet and profiles, various technologies to produce tailored blanks and profiles have been developed [1,2]. In earlier work [3] it has been shown that Strip Profile Rolling (SPR) can be used to produce metal strips with a predefined thickness distribution across the width of the strip. Building upon this knowledge, in two subsequent papers the extended goal of the project is presented. Therein is demonstrated that Strip Profile Rolling can be applied very effectively using a combination of roll forming (part 1) as well as further processing by roll forming (see part 2) to allow for the production of profiles with varying wall thickness in their cross section. To achieve the goal of part 1, a numerical model describing SPR was developed and used to study the influencing process parameters on spread and bulge formation. As a result of this parametric study, an optimized roll design and rolling sequence was developed to produce a demonstrator strip on a 12 stand roll forming mill manufactured by the company Dreistern [4]. Starting with a conventional strip out of DC01 steel (width 170 mm, thickness 2.5 mm), 29 rolling passes were necessary to achieve the desired geometry (width 186 mm, thickness 2.5 mm with a longitudinal groove being 64 mm wide where the thickness is reduced to 1.5 mm). In the second part of the process chain the coils produced by Strip Profile Rolling were successfully roll formed into a circular tube of 60 mm.     

工作辊弯辊力对热轧带钢凸度的影响

为了建立高精度的热轧带钢凸度计算数学模型，采用影响函数法开发了四辊轧机热轧带钢凸度影响率计算软件；系统地研究了工作辊弯辊力对带钢凸度的影响规律。得出了工作辊弯辊力影响率基本值和工作辊直径、单位宽度轧制力、压下量对弯辊力影响率修正指数的6次项拟合系数，建立了高精度工作辊弯辊力影响率的计算模型。为优化板形控制参数提供了理论依据。     

LVC工作辊辊型的板形控制性能研究

提出一种新型线性变凸度工作辊辊型即LVC辊型,这种辊型实现了辊缝凸度调节与板宽成线性化.用承载辊缝调节域和承载辊缝横向刚度这两个基本板形控制性能来验证LVC工作辊的板形调节能力,并将LVC工作辊应用到实际生产中,经过计算和比较可以看出LVC工作辊辊型具有较好的实用性.在工作辊辊型的研究上具有一定的新颖性.     

Study on Error Compensation Method of Online Roll Profile Measurement

Flatness and surface quality are important quality indexes of strip steel, and roll wear will directly affect the product's flatness and surface quality. Online roll profile measurement technology can obtain the information of roll profile in real time, guide the optimization of roll change rhythm, and improve the flatness control ability of rolling mill and surface quality of strip product. However, the error caused by roll displacement, clearance, roll thermal crown, and other factors is usually the same order of magnitude as the roll shape or roll wear, or even one order of magnitude higher. So error compensation is the key to ensuring the accuracy of online roll profile measurement. Herein, the position measurement technology of the roll bearing block is considered in the online roll profile measurement, and the measurement error caused by the deviation of the roll axis is separated. The thermal crown model is established to separate the measurement errors caused by the thermal crown. The error compensation model of online roll profile measurement is established, and the simulation calculation is carried out. This error compensation method is of great significance to improve the accuracy of online roll profile measurement and realize the fine management of mill roll in service.     

热轧生产轧辊降耗实践

对鞍钢热轧带钢厂1700生产线影响轧辊降耗的主要因素进行了分析,在采用常规方法降低辊耗的基础上,又制定了特殊的降辊耗措施:加大轧辊有效直径,采用切水板密封检测方法以及断辊重铸技术等,实施后单位吨钢消耗降低了0.15 kg,降本效果显著。     

不锈热轧带钢轧辊材质的发展

不锈热轧带钢精轧机组工作辊材质问题是决定产品表面质量、板形、生产效率和成本的重要因素。介绍了现用轧辊材质的状况及使用高速钢的轧辊的作用和效果。     

HC轧机辊型曲线优化

HC轧机采用中间辊轴向窜动技术,使轧机的横向刚度显著增加,提高了板形控制能力。但由于中间辊轴向窜动后,在工作辊与中间辊、中间辊与支撑辊间形成接触压力峰值,导致轧辊局部磨损及带材表面质量问题。建立了HC轧机板形和断面形状计算模型,研究了支撑辊及工作辊辊型曲线对辊间接触压力分布的影响规律,在此基础上优化了1220HC轧机支撑辊及工作辊辊型曲线。理论计算及工业生产试验表明,在保证轧机板形控制能力前提下,在HC轧机支撑辊及工作辊上采用合适的辊型曲线,可将支撑辊与中间辊间的接触压力峰值降低20%以上,将工作辊与中间辊间的接触压力峰值降低10%以上,从而避免辊间接触压力峰值带来的轧辊局部磨损及相应的带钢表面质量问题。     

压型板辊弯成型过程数值模拟

针对压型板辊弯成型过程中带材变形复杂、成型规律难于掌握的问题，应用显式动态有限元模块ANSYS／LS-DYNA对压型板辊弯成型的全过程进行模拟分析。动态分析板带从前一架进入下一架的成型过程，板料可在两架间同时各自变形。发现应力的集中区域存在于变形过渡区和辊缝中心线下的主要变形区；横向弯曲应变大都集中于弯曲角处，应变值随成型角增大而增大。模拟结果证实通过有限元模拟探索冷弯成型规律的可行性。该方法对于分析其他复杂断面型钢的成型特点具有一定的理论和实际意义。     

热连轧机工作辊动态负载辊缝计算与应用分析

根据热连轧机工作辊热凸度与磨损计算方法,结合辊系弹性变形和金属塑性变形计算理论,在现场应用与模型参数优化的基础上,建立了工作辊在线辊型及动态负载辊缝计算模型。根据实际轧制计划,将模型计算结果与实测结果进行对比,验证了计算模型具有较高的精度,能够满足工程计算和分析的需要;此外,计算分析了工作辊在线辊型和不光滑辊面对出口带钢断面形状的影响,并提出了带钢断面形状的优化方法,为提高热连轧机出口带钢的板形质量提供了理论依据。     

超薄规格热轧带钢生产技术

薄规格热轧宽带钢以热带冷的趋势正逐渐扩大,具有广阔的应用前景,但生产难度大。珠钢通过严格控制钢水成分、温度的波动变化范围,定期检测铸坯对中、楔形、镰刀弯、温度均匀性来促进连铸、加热炉工序工艺及设备精度的持续改进,解决铸坯楔形、镰刀弯、变形抗力不均等问题;通过优化加热炉炉膛气氛、改善炉辊运行状况,调整工作辊冷却,合理设计轧制计划,解决过早发生麻面质量缺陷问题;发明预调板带对中度的轧钢操作法,大幅降低卡钢、甩尾事故和浪形缺陷;通过设计花纹辊新花形、选用合适轧辊材质及轧辊凸度,解决超薄花纹板生产难脱槽、易崩口和易中间浪的问题;最终实现了超薄规格热轧宽带钢大批量生产,h＝1.0mm～1.35mm普通碳素结构钢超薄规格热轧板比例达到30%,h＝1.0mm～2.0mm 超薄规格热轧花纹板比例达到74%,h＝1.0mm～1.8mm超薄规格热轧花纹板比例达到28%。     

板宽和轧辊凸度对热轧板带凸度控制的影响

针对通常在研究板带宽度变化对出口板凸度的影响时没有考虑辊系凸度这一因素,应用三维刚塑性有限元法、影响函数法、三维弹性有限元法,开发了一个分析板带热轧过程的分析软件.利用该软件研究了支承辊、工作辊的凸度从-0.5mm到0.5mm变化时,板宽的变化对出口带钢板凸度的影响规律.结果表明:支承辊、工作辊凸度为0时,板凸度随板宽...     

轧辊热凸度实例分析

轧辊热凸度直接影响着热轧带钢的板形质量,而轧辊冷却水系统和轧制计划都与轧辊热凸度有着密切的关系。着重分析实际生产中常见的一些轧辊热凸度曲线以及这些曲线产生的原因,对生产控制过程产生重要．的指导意义。     

热轧Al-Zn-Mg-Cu合金板材表面黑条缺陷研究

研究了热轧高锌合金板材表面黑条缺陷的成分、产生机理及消除方法。     

Determination of Optimal Work Roll Profile for Cold Strip Mill

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板带在排辊成型过程中的仿真研究

通过采用大型非线性有限元软件Marc对板料的排辊成型过程进行了模拟,获得了板带各机架截面处和沿板带纵向的等效应力分布规律。分析了排辊对板带接触作用的成型特点,为排辊成型机组的孔型设计以及排辊调整提供了理论依据。     

Numerical Simulation and Sensitivity Analysis of Parameters for Multistand Roll Forming of Channel Section With Outer Edge

 Cold roll forming is a high production but complex metal forming process under the conditions of coupled effects with multi factor. A new booting finite element method (FEM) model using the updated Lagrangian (UL) method for multistand roll forming process is developed and validated. Compared with most of the literatures related to roll forming simulation, the new model can take the roll rotation into account and is well suited for simulating multistand roll forming. Based on the model, the process of a channel section with outer edge formed with twelve passes is simulated and the sensitivity analysis of parameters is conducted with orthogonal design combined FEM model. It is found that the multistand roll forming process can be efficiently analyzed by the new booting model, and sensitivity analysis shows that the yield strength plays an important role in controlling the quality of the products.     

3417B轧辊磨床磨辊辊花消除的实践

分析3417B轧辊磨床在使用中产生辊花的原因,提出消除此类辊花的方法,并介绍了现场维修处理过程。