FEM Analysis and Forming Limit in Burring Process of Large Diameter Steel Tube

Abstract

This paper describes FEM analysis and the forming limit in burring processing of large diameter steel pipe. The pipe in this paper is SGP pipe. The large diameter pipes such as 165.2 mm are used for a plant as a flow channel of gas and liquid. A burring process of pipe is generally for forming the branch. The burring process is achieved by drawing of die from prepared hole. And the branch pipe is welded to the formed pipe. This process has some problem. One is the forming limit of pipe, and the other is needed to machining the end surface to be welded. Therefore, in this study, the forming limit of SGP pipe was estimated by FEM analysis of burring process. The pipe used in this study is an SGP pipe with a diameter of 165.2 mm and a wall thickness of 5 mm. The parameters used for criteria for forming limit are the maximum shear stress and the equivalent strain. As a result of comparing the analysis result and the experimental result, it was judged that the maximum shear stress is 350 Pa and the equivalent strain is around 0.8 is the forming limit of the 150A SGP pipe.