FEM Simulation Research On Large-Sized Straight Weld Pipe's Rounding And Sizing Process

At present, straight weld pipes are widely used in high-pressure natural gas pipelines and subsea pipelines. in the production process, mechanical expanding is the main ways to correct the error geometry. However, because the ellipticity of a small number of the weld pipes' is relatively large, mechanical expanding is difficult to fully meet the requirements of the products. And the structural of the mechanical expanding machine is complex, and the machine has a high price, what's more, this process has many factors to impact the quality of the products. Now, the pipe manufacturing sector has begun to seek a more simple processing program to supplement the mechanical expanding. Supplement the shortage of mechanical expanding or displace mechanical expanding. In this paper, we propose a pipe geometry error correction method, we call it Rounding and Sizing, and we make the FEM simulation research of of this method.We made a large number of numerical simulation of Rounding and Sizing with MARC. Based on the simulation of Rounding and Sizing of the pipes with the diameter of 1219mm, thickness of 33mm, 27.5mm, 26.4mm and 22mm, we analysis how the diameter of the mould affect the forming of the Rounding and Sizing process.The Rounding and Sizing process is a plastic deformation process relates to the factors such as tube specifications, mould diameter, deformation and so on, the ultimate size of the products depends on the accuracy of the combined effects of these parameters. This paper makes products ellipticity as the objective function, the mould diameter, geometrical form and ellipticity of the tube as the variables of the objective function, to optimize the calculation, provides a theoretical basis for Rounding and Sizing process, all of these have theoretical significance and practical value.