【作者】 罗洲；

【导师】 常志华；

【作者基本信息】 武汉理工大学 ， 材料加工工程， 2004， 硕士

【摘要】 环件轧制是一种生产无缝环件的特种加工工艺，它是通过局部连续轧制方法，将小直径厚截面的环形毛坯逐渐辗扩成大直径薄截面的环件，它具有省力，节能、节材、生产率高、生产成本低、产品范围广等显著特点，在工业领域有着广泛的应用。 本文基于环件轧制理论和有限元理论，建立了环件轧制过程有限元分析计算模型，并使用动力显式算法进行了计算。通过模拟分析比较，揭示出了环件轧制过程中的金属流动规律：轧制时，环件外侧的变形最大，厚向中心部位变形最小，内侧的变形程度介于中间；环件内外环面的压应力分布和变化规律：在垂直于环件轴线的对称面上，压应力分布近似对称状态，而且在对称面上的应力最大，往端面方向开始减小；指出了环件轧制中轧辊与环件摩擦对环件成形的影响：对于环件的宽展变形，摩擦的影响很小，可以忽略；分析了环件进给速度对环件成形的影响并阐述了环件厚向中心部位凹陷产生的原因，提出防止凹陷的措施：在轧制时，尽量使用快的进给速度有利于防止端面凹陷的产生；研究了导向辊位置对环件成形以及轧辊受力的影响：导向辊的位置对环件的宽展变形影响很小，但对轧辊的受力影响较大，当导向辊的中心位置位于毛坯初始中心位置之上时，驱动辊和芯辊的受力相对较小，这是导向辊导向时优先考虑的位置。 本文使用有限元分析方法，对异形截面环件过程工艺参数进行了设计和规划，模拟出了环件轧制过程中出现的缺陷，阐明了缺陷产生的原因及改进方法；利用设计好的工艺参数进行分析的结果和试验结果进行了比较，两者达到了较好的吻合。更多还原

【Abstract】 Ring rolling is a specialized rolling process for manufacturing seamless rings, in which the diameter of the ring increases as the ring cross-section decreases by rolling. It has many characteristics such as saving forming force and production cost, increasing utilization ratio of energy and material, improving productivity and widening processing range of ring products etc. It is widely employed in many industrial domains.In this paper, based on the theories of finite element method and the theories of ring rolling, the calculation model of ring rolling processes has been established and calculated by dynamic algorithm finite element program. Detailed numerical results are obtained: the deformation of the ring-driven roll interface is larger than that of the ring-idle roll interface. In the center domain, the deformation of the ring is smallest. The distribution of normal pressure stress along the ring-roll interface is radial symmetry and the pressure stress is largest in the symmetry plane. The effect of the friction between rolls and ring can be ignored and the effect of the spread velocity of rolling on the deforrration of ring is illustrated. Then the cause and elimination of fishtail defect are investigated: a relative faster spread velocity is helpful 10 eliminating the defect. The position of the guide roll almost has no effect on the deformation of the ring, but has the important effect on the force appeared in the roll. Then the optimal position has been suggested the center position of the guide roll should be over the center of the green blank of ring.The simulation of profile ring rolling has been performed to get the process parameters. As a result, the rolling defect has appeared and the cause has been illustrated. The result has a good agreement with the experimental data.更多还原