A study on the flow forming of cylindrical tubes

This paper presents studies conducted on the flow forming of cylindrical tubes using a rolling mechanism. A rolling die with six rollers was designed. On each roller, a sensor, which measured the force acting on the roller, was incorporated into the die. At the top of the mandrel, another force sensor was integrated to monitor the tension acting on the bottom of the tube being rolled. Flow forming was carried out for different deformation ratios. The forces on both the roller and the mandrel were found to increase with increase in the deformation ratio and with different lubrication conditions. Besides the influence of the deformation ratio, the forces were also strongly dependent on the size of the rollers. In the tests, three different sizes of rollers were selected. Although a high deformation force is required for the big roller, the surface finishing using a big size of roller is better for using smaller rollers. Theoretical analysis on the force of the flow forming was also carried out to study the influence of the different parameters.