Investigation of forming of end parts in pipe tension reduction using QForm program

Abstract

The paper deals with issues of longitudinal stresses during pipe rolling pipes on a three-roll stretching and reduction mill. Opportunities and problems in pipe reduction under tension are described. A research program aimed on reduction and evaluation of all input parameters that affect the parameters of the end parts of pipes based has been developed on the finite element model (FEM) base. Computer study on the FEM basis of stretching and reduction rolling of pipes using the Qform-3D program was carried out. When setting up the experiment using the FEM, the relative variation of the pipe wall thickness at the end parts of the pipe was chosen as the parameter for examination. Reduction of the pipe in its diameter in the pass, ovality of the pipe, geometric parameters of the initial pipe, front and rear tension of the pipe and friction coefficient were the main factors that determine the studying values. Geometric parameters of the end parts of the simulated pipe were measured after modeling. A statistical analysis of the results of a computational experiment of data on variation of pipe wall thickness was carried out. Regression dependence was built using the MATLAB program, and the most significant factors were selected according to the level of their importance. The model that describes the behavior of wall thickness during rolling in a stand of a stretching and reduction mill has been constructed.