No abstract

Tube spinning is a metal forming process used to manufacture axisymmetric products. This study chose a seamless thick-walled steel tube to manufacture a high pressure vessel. Finite element analysis was successfully applied to the neck-spinning process of a thin-walled tube; however, previous research has not investigated the neck-spinning process of thick-walled tubes. Therefore, the aim of this research was to investigate numerically the neck-spinning process of thick-walled tubes at an elevated temperature. The commercial software Abaqus/Explicit was adopted in the simulation. This paper compares experimental and simulation results on thickness distribution and outer contour of the spun tube. During the final stage, the average deviations between the simulation and experiment were 6.74% in thickness and 4.97% in outer contour. The simulation results correspond with those derived in the experiment.

The tube spinning process is a metal forming process used in the manufacture of axisymmetric products, and has been widely used in various applications. In this paper, the neck-spinning process was applied to form the neck part of the tube end at an elevated temperature. The spun tube was used as a high pressure CO2 vessel, which is a component of motorcycle airbag jackets. An uneven surface will occur on the tube surface if the thickness distribution of the tube is not uniform after the neck-spinning process. This is because different thicknesses result from different contractions during the cooling stage. For this reason, the aim of this research was to numerically investigate the roller forming path to improve the thickness distribution of the tube during the neck-spinning process. The finite element method was used to simulate the neck-spinning process of the tube at an elevated temperature. For the construction of the material model, special uni-axial tensile tests were conducted at elevated temperatures and various strain rates, because the material is sensitive to strain rates at high temperatures. This paper compares the experimental and simulation results of the thickness distribution and the outer contour of the spun tube. The validated finite element model was used to investigate the influence of the roller forming path on the thickness distribution of the tube. The thickness distribution of the tube formed by a curved path was found to be more uniform than for the tube formed by a straight path. Finally, the optimization technique was used to find the optimal forming path, and the optimal result was verified experimentally.