【作者】 时旭；

【导师】 刘相华；

【作者基本信息】 东北大学 ， 材料加工工程， 2005， 博士

【摘要】 冷轧薄带钢生产中的板形控制问题是复杂和难以解决的问题。本文以东北大学和宝钢的合作研究项目“冷轧板形机理研究—原始板形对出口板形的影响及1420mm冷连轧机组板形控制对策研究”为背景，应用MSC．Marc有限元软件，对薄带钢冷轧过程进行了数值模拟。采用弹塑性静力隐式算法，耦合分析了带钢与辊系、工作辊与支撑辊的变形场和应力场。该项研究工作对轧制过程有限元模型以及现场生产中的板形控制具有重要的指导意义。主要研究工作如下： 1) 为了适应不同模拟的需要，建立了二维刚性辊轧制模型、二维弹性辊轧制模型、三维刚性辊轧制模型、三维弹性辊轧制模型、三维四辊轧制模型及四辊CVC辊系变形模型。这些模型全面描述了不同状态的板带轧制过程。应用有限元模型对带钢生产过程进行了模拟，模拟结果与实测值比较表明了模型的精度及可靠性。 2) 采用三维四辊轧制模型和二维弹性辊轧制模型，得到了轧制压力的横向及纵向分布特点，讨论了轧制条件对轧制压力分布的影响。对轧制力结果分析表明，摩擦系数每增加0.01轧制力增加0.25MN；前后张力每均匀增加100MPa轧制力减小1.2MN；带钢变形抗力每增加100MPa轧制力增加1.25MN；带钢压下量每增加1％轧制力增加约0.1MN。 3) 采用弹塑性有限元方法，分析了轧制条件对板凸度和带钢边部减薄的影响，以及张应力及带钢宽度对带钢横向变形的影响。在对带钢横向流动的分析中，得到在带钢中心区金属向中心流动，而且在距边部60～75mm处金属向中心流动量达到最大；在带钢边部金属明显向外流动，这是由于边部减薄及骤减引起的；根据模拟的结果及现场生产的带钢边降特点，解释了拉缩现象。在对带钢弹性变形分析中，发现在带钢入口处存在很小的弹性变形使带钢在此处的厚度增加，称这种增加为“突起”。研究了前后张应力及带钢压下量对带钢入口突起和出口弹性回复的影响，得到了突起和回复变形沿带钢宽度的分布规律。 4) 对辊系的变形进行了模拟，分析了轧制条件对工作辊弯曲变形、支撑辊弯更多还原

【Abstract】 The shape control problem of thin strip in cold rolling is complicated and difficult to solve. Based on the cooperative project of BaoSteel and Northeastern University, "Studies on mechanism of cold rolling— studies on the effect of original shape on exit shape and measurements of shape control for 1420 mm cold tandem mill", in this dissertation the Elastic-Plastic FEM was used to analyze the thin strip cold rolling process by MSC.Marc software. The static implicit expression of elastic-plastic FEM was utilized to simulate couple field of displacement and stress between strip and rolls, work roll and backup roll. The dissertation will be a worthy reference for the FEM model of rolling process and shape control in practical rolling process. The main studying work and results are shown as following.1) To meet the requirements of different simulation, the rolling model of 2-D rigid roll, 2-D elastic roll, 3-D rigid roll, 3-D elastic roll, 3-D 4-high mill, and the rolls system deformation model of 4-high CVC mill were created. These models were necessary to investigate different thin strip rolling process. Based on the simulation of practical rolling process, the results of simulation agreed well with the measured value, it was shown that these models had high precision and authenticity.2) By applying 2-D elastic roll rolling model and 3-D 4-High rolling model, the rolling force and pressure distribution had been analyzed, and the effect of different rolling conditions on rolling pressure distribution had been discussed, too. It was clearly that the rolling force will be increased 0.25MN while the friction ratio increased 0.01; the rolling force will be decreased 1.2MN while the forward and backward tension increased lOOMPa respectively; the rolling force will be increased 1.25MN while the resistance of deformation increased lOOMPa; the rolling force will increase 0.1MN while the reduction increased 1%.3) Based on elastic-plastic FEM, the effect of rolling condition on strip crown and edge drop, the effect of tension and strip width on strip deformation along strip width had been analyzed. It was found that in the central area of strip, metal would flow to更多还原