Spinning process optimization and microstructure of stainless-steel welded pipe

Defects, such as cracks, typically occur in the spinning process of ternary catalyst shells. This study investigates the optimization of spinning process parameters to prevent such defects. In this regard, an orthogonal simulation was performed using a finite element model of the spinning process of a ternary catalyst shell. Moreover, spinning tests using a 439 stainless steel welded pipe were conducted to verify the simulation results. Thus, the microstructure, hardness, and quality of formed parts are analyzed. The simulation and test results showed that when the spinning temperature is 1000 degrees C, the roller fillet radius, roller speed, and feed ratio are 5 mm, 40 r s(-1), and 1.2 mm r(-1), respectively. In addition, the error rates of the forming thickness, port diameter, and roundness error are 1.37%, 1.25%, and 4.8%, respectively. These results verified the accuracy of the simulation. Furthermore, no defects were generated during spinning, and the spinning quality was high. The feed ratio was the main factor affecting the roundness error, followed by the roller speed. As deformation increased, hardness increased, and the crystal size decreased. The results of this study can provide crucial theoretical guidance for practical spinning applications.