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. An orthogonal simulation is performed using a finite element model of the spinning process of a ternary catalyst shell. The simulation results are verified by performing spinning tests using a 439 stainless steel welded pipe. The microstructure, hardness, and quality of formed parts are analyzed. The simulation and test results demonstrate that when the spinning temperature is 1000 °C, the roller fillet radius, roller speed, and feed ratio are 5 mm, 40 r/s, and 1.2 mm/r, respectively. In addition, the error rates of the forming thickness, port diameter, and roundness error are 1.37%, 1.25%, and 4.8%, respectively. This verifies the accuracy of the simulation. No defects are generated during spinning, and the spinning quality is high. The feed ratio is the main factor that affects the roundness error, followed by the roller speed. As deformation increases, hardness increases and the crystal size decreases. The results of this study can provide important theoretical guidance for practical spinning applications.

Copolymerization of lactide, epoxides and carbon dioxide: a highly efficient heterogeneous ternary catalyst system

The controlled copolymerization of mixed monomers that usually imparts distinct advantages into single polymer chains and requires a single versatile catalyst remains a key challenge in polymer chemistry.

Efficient ternary catalyst system for the copolymerization of lactide, epoxides and CO2: new insights into the cooperative mechanism

Ternary catalyst system (TCS) is an emerging type of catalysts for the synthesis of multiblock copolymer of lactide (LA), epoxides and CO2. For our previous ternary catalyst system (SalenCoIII-dinitrophenol (DNP),...