Cross Wedge Rolling Convergent Forming Of Hollow-ware

With the rapid development of cross wedge rolling technology, cross wedgerolling forming process of hollow pieces has being researched by people. In the rollingprocess of cross wedge rolling, the rotating conditions of hollow pieces was poor thanthe solid pieces. The cross-section of hollow pieces was tend to ovalization, andaffected the forming effect, even caused flattening or instability phenomenon. Itseriously affected the quality of workpiece forming.Cross wedge rolling technology was used to research hollow pieces heal formingin this topic. Molds in different scenarios were established by UG three-dimensionalsoftware. Forming process of blank was simulated by Deform finite element software.Compared simulation results, and analyzed forming mechanism, and improved betterforming programs, and the best forming program has been acquired. The best formingprogram has been adopted in the test and got forming workpieces.Observed simulation results, and analyzed the forming mechanism, effective stress,effective strain and temperature distribution. Got the following conclusions: Theforming effect of gradually deformed rolling program of variable angle was poorer thanthe intermittent deformed rolling program of constant angle, and improved betterforming program; Forming angle design had a greater impact on workpiece forming. Inrolling process, the workpiece is turned6.5circles and it is deformed in the former5circles and the forming angle increases linearly from0°to3.6°; the sixth circle isforming stage and the forming angle is3.6°constant, and the6.5circle is unloadingstage; Imposing a certain speed to guides was conducive to outer surface forming ofworkpiece.In the rolling experiment, collecting and organizing experimental data, obtainedthe following rules: The relationship between maximum reduction of roll and the axialelongation, outer diameter shrinkage, inside diameter shrinkage was incomplete linear.When the amount of reduction within a certain range, with the increase of the amount of reduction rolls, axial elongation of the workpiece increases, the shrinkage of insideand outer diameter followed linear increase, and the inside diameter shrinkage wasmore and more obvious effected; When the rolling reduction reached a certain value,the axial elongation attained maximum value4.01mm.Shut results effect of inside andouter diameter attained limit value8mm or13mm; If we continue to increase theamount of reduction, workpieces can not be formed.