【作者】 陈仙凤；

【导师】 金杰；

【作者基本信息】 浙江工业大学 ， 材料加工工程， 2008， 硕士

【摘要】 在分析了国内外板材轧制数值模拟发展及现状的基础上,通过有限元法对轧制过程进行了数值模拟,以探求轧制过程中的规律,为合理制定工艺参数,优化工艺结构提供技术支持和理论依据。本论文研究的主要内容有:(1)通过1Cr13高温拉伸试验研究400℃、500℃、600℃、650℃、700℃温度点下的屈服强度,抗拉强度等基本力学性能。利用试验得出的400℃、700℃温度点下的应力应变数据,在DEFORM-3D平台上对其它温度点进行拉伸试验数值模拟。结果直观地显示了各阶段应力应变分布及试样的变形过程,仿真屈服强度、最大抗拉强度等与试验实测值吻合较好,随着有限元软件的不断发展,数值模拟有望成为拉伸试验的另一手段。利用该数值模型外推得到了900℃、1000℃、1100℃的应力应变曲线,从而为本构模型的建立奠定基础。为该材料轧制模型的建立提供必要的力学性能数据,以便热轧模拟能够更精确的进行。(2)对1Cr13材料进行热轧数值分析,用云图直观地反映出轧制各个阶段应力应变分布情况,并通过多组试验对影响轧制压力的参数如轧制温度、轧辊转速、压下量、轧板厚度进行了分析,得到了轧制温度、轧辊转速、压下量、轧板厚度对轧制压力的影响规律。(3)将模拟轧制压力值与西姆斯热轧轧制力公式计算出的理论值进行比较,两者的变化趋势一致,但有一定的误差存在,对误差存在的原因进行了分析。(4)通过对影响轧板应变程度的参数如:压下率、宽高比(B/H)、轧制温度、轧制转速等进行研究,得到了轧制应变渗透到中心层的临界值,并分析了压下率、宽高比(B/H)、轧制温度、轧制转速对应变以及板材侧形的影响规律。用点跟踪法对不同厚度层上的应变进行跟踪,分析了在厚度层上应变分布规律。(5)对热轧温度场和应力应变场进行了耦合数值模拟,分传送阶段、轧制进行阶段、喷水冷却阶段、返温阶段进行热轧模拟,得到了各个阶段轧板温度场的分布规律、应力应变场分布规律。研究了典型节点温度随时间的变化规律,分析了耦合应力应变场的变化规律,与非耦合应力应变场的变化规律进行比较,在厚度方向的最大应变从外表面转移到了次表面。并分析了轧制初始温度与轧制转速变化对轧制压力的影响规律,初始轧制温度以及轧辊转速对轧制温度场的影响规律。更多还原

【Abstract】 Based on the analysis of the development and present situation of the numerical simulation of the plate rolling process both home and abroad, a FEM model of the rolling process are created. On the premise of being tested the reliability, the models are used for simulating the rolling process, and for searching some regularities of the rolling process, as a result, some problems can’t be solved by industry experiments can be solved in this way conveniently, some technical and theoretical supports for the optimization of technology can be provided.The main contents of the subject as following:The tensile properties of 1Cr13 was studied by high temperature tensile tests on 400℃、500℃、600℃、650℃、700℃. It provides the necessary mechanical properties data for hot rolling. Based on the experimental data of 400℃、700℃, the tensile tests of 1Cr13 on other temperatures such as 900℃、1000℃、1100℃were simulated on DEFORM-3D. It showed the distribution of stress and strain at various stages and the deformation process of the sample intuitively. Meanwhile, the results of simulation were verified by the experiments. It was the foundation for the establishment of the rolling model. Numerical simulation is expected to become another means of tensile test with the development of the FEA Software.Rolling model was established, and the factors that affected the rolling resistance were studied. Based on the numerical simulation, the relationship of rolling temperature, roller speed, volume reduction, rolling plate thickness and rolling resistance was studied. Then comparison of the simulated rolling results and the calculated results with Sims rolling pressure formula was studied, and the error of them was analyzed. The metal was flowing at the length direction and breadth direction when the hot rolling was going. So the strain on the two directions was altered. The effect of rolling temperature, rotation rate, volume reduction and the ratio of rolling plate breadth and thickness on the strain was studied. The critical data of the volume reduction and the ratio of the breadth and thickness which affected the strain depth were analyzed.Taking use of the model of the rolling process, the change of the rolled piece temperature field was simulated. The temperature field distribution, stress field distribution and strain field distribution of rolling plate on various stages was studied.As the development of FEM software, the simulation result will be more accurate. It can optimize the technique of hot rolling and provide the technical support.更多还原