60kg/m钢轨轧制变形过程的有限元分析

【作者】 郭华；

【导师】 钟毅； 梅东生；

【作者基本信息】 昆明理工大学 ， 材料工程， 2005， 硕士

【摘要】 随着数值模拟技术和计算机技术的发展,有限元法在解决大型、复杂的工程问题的能力和效率大大提高,各种大型通用商业有限元分析软件如ANSYS、NASTRAN、MARC等已经广泛应用于国防、航空航天、汽车、机械制造、冶金等各个工业领域。在冶金工业的机械设计、锻造、焊接、金属热处理、钢铁冶金、轧钢等各个专业领域得到较为广泛的应用。对于棒、线、型材轧制变形的有限元模拟,主要侧重于轧件三维变形状况的解析,通过模拟了解轧件变形过程中的塑性流动情况、轧制压力分布、产品形状、尺寸等,普遍采用三维刚塑性有限元进行模拟。同时,与板材轧制过程模拟相比,棒、线、型材轧制变形的模拟更为困难,其几何形状更为复杂、轧件变形不均匀、轧件与轧辊表面接触和脱离很难判定,不过,近年来,在复杂断面型钢变形过程的模拟方面仍取得了很大进步。 在钢轨轧制变形过程中发生了复杂的三维金属流动,采用传统的经典理论解析方法几乎不可能求解,为此,本文借助非线性有限元分析软件MARC对其变形过程进行分析。通过实验室研究,获得了PD3钢轨的材料参数和热传导参数,建立了全三维大变形热力耦合弹塑性有限元模型,成功地实现了60kg/m钢轨精轧变形过程的数值模拟,清晰地观察到了轧件的不均匀变形和畸变过程,得到了轧件在孔型中延伸和宽展情况、等效应变、等效应力以及温度分布、轧制压力大小,通过作者编写的PYTHON程序,得到了钢轨轨高、底宽的变形情况,研究获得了不同工艺参数变化如温度变化、压下量变化、轧前来料尺寸变化、摩擦系数变化、轧辊磨损等对断面尺寸精度的影响规律,分析结果与现场试验结果吻合良好,对实际生产的轧机调整和孔型设计具有指导意义。更多还原

【Abstract】 Along with the development of computer technology and numerical simulation technology, the capacity and efficiency of solving large and complicated engineering problems used by FEM have been greatly improved. The FEM software such as ANSYS、NASTRAN、 MARC,has applied on the National defence,Aviation & Spacelight,Auto,Machine making,Metallurgy,and so on.In the metallurgy industry, FEM has been used in the speciality field such as Machine designing,Forging,Metal hot-treatment,Iron making & Steel making,Steel rolling.For the numerical simulation of rolling deformation of bar,wire and section,mailly focus on the 3D deformation,plastic flow,rolling load distributing,production profile,size,and it is more difficult than that of plate,because it’s profile is more complex,the deformation is asymmetry,it is more difficult to determine the contact and separation of rolling material and roller surface,but,the numerical simulation of deformation of complex section improved greatly in near years.The deformation of rail rolling occurred complicated 3D metal folw, it is impossible to solve the metal deformation with the classic steel rolling theory.In this paper, to analyze the deformation of rail rolling used by MARC. In the lab,obtained the material parameters and heat exchange parameters of PD3 rail, based on the 3D large deformation thermal-mechanical coupled elasto-plastic FEM, clearly observed the asymmetric deformation, obtained the elongation, width-broaden, distributions of strains, stresses,temperatures and rolling load, obtained the accurate size of rail height and width by the PYTHON language program written by author, obtained the rule of the effect of the change of process parameters such as temperature, reducement, the size before rolling,friction coefficient and roller wear on the precision of rail profile, the law of deformation from the FEM is accordance with the results of spot, the results are important to guide practical production.更多还原