Ring rolling process is widely used in production of seamless rings for automotive and aerospace industry. This thesis presents a summary of ring rolling technology, machine and processes. In addition, it investigates the manufacturing of weld-neck flanges by this method. A three-dimensional elastic-plastic finite element simulation using ABAQUS/Dynamic Explicit software was made to study the deformation a rectangular section ring of tellurium-lead material. The guide rolls modeled by using axial connection spokes. The result including the rolling force and torque of this simulation are compared with those of the other researchers used the thermal spokes method in modeling the guide rolls. The thermal spokes are replaced instead of the guide rolls to ensure the accuracy of modeling and simulations. The three-dimensional elastic-plastic finite element model of L-section rings that is used to investigate the forming of the weld-neck flanges. Lead-tellurium material was used to model the hot steel in room temperature with good accuracy and established under ABAQUS/Dynamic Explicit software. Based on this model the optimum pre-form for forming a weld-neck flange was achieved. From the simulations some results including the effect of angular velocity of main roll, the roll force and torque are also obtained. Plastic penetration is a necessary condition of profile ring rolling. During the process it was observed that the feed rate had a significant effect on cavity formation at the outer surface of flange, enhancing surface defects for slow feed rates at smaller reductions, rather than for fast closure rates. The simulations were performed to reduce the cost of experiments. The final main roll was designed and manufactured to match the forming of final product. It is then assembled on the ring rolling mill of Isfahan University of Technology. Experimental values were compared with that of the simulations in forming the weld-neck flange. Good agreements were found with this comparison. This survey will be specially valuable for industry personnel engaged with the selection and implementation of ring rolling lines and process planning engineers working with ring rolling companies. Key Words : Ring Rolling, Weld-Neck flanges, Finite Element Method, Pre-form Design, Experiment.
