Impact of sizing process in ERW pipes through circular and edge forming

Pipes are fundamental elements utilized in the construction of pipelines over extended distances to transport gas, oil and their derivatives. These pipes can be produced using electric resistance welded (ERW) cold forming process, widely employed in the petroleum industry. This study numerically investigates the collapse pressure of pipes, a crucial metric for offshore application. The entire manufacturing process of ERW pipe was modeled through numerical analysis with ABAQUS. Two flower patterns, circular forming (CF) and edge forming (EF), were used to design the forming rollers for each simulation stage, based on geometry-based calculations. A material model integrating both strain hardening and the Bauschinger effect was employed. Different pipe cross-sections were modeled during the simulation. The enhancement of collapse pressure in pipes manufactured using the two forming methods were examined through the sizing process with various sizing ratios. The results indicate that collapse pressure increases with greater sizing ratios, especially for pipes with a higher thickness-to-diameter ratio (t/D). The collapse pressures of two forming methods were compared, revealing that CF outperformed EF. Finally, ovality and yield strength under compression in the circumferential orientation were investigated as contributing factors to the enhancement of collapse performance during the sizing process.