The Research On Large Pipe End Circular Correction Technology

The pipe end setting-round is an important link of the large pipe production process,on one hand in order to eliminate the residual stress of the tube member, to improve theyield strength of the tubular member, on the other hand in order to improve thedimensional accuracy of the end region of the pipe member and make two fittings weldingjoint conveniently. Therefore, it takes on very important practical value to go into the largepipe end entire diameter straightening-round process.In this paper, it adopts the finite element numerical simulation and experimental forstudying a large pipe reeling straightening mouth process.First of all, basing on setting up the three-dimensional modeling of straight tubuleswith rigid-end, the numerical simulation to the reeling and straightening-round process hasbeen proceeded, with using the finite element simulation software ABAQUS. It can beseen through the numerical simulation results that the wall thickness of the end and thesize of outer diameter has been changed a little, its geometry is relatively regular, and itsovality has been greatly improved. At the same time, a thorough inquiry has beenperformed in regard to the effect of mold and process parameters in the process on thequality of tube after setting round.Then, the numerical simulation has been carried on the fittings reeling andstraightening-round process about Elbow and tee. Analog results tell that the process has asignificant effect on improving the quality of elbow and the tee pipe member in the sameway.Finally, the reeling and straightening-round process is tested on the end oftube,whose material is of steel20, whose outer diameter is of76mm and whose thicknessis of4mm. Experimental results indicate that after reeling and straightening round, theovality of tube end has been significantly improved. Thus it verifies that it is viable toimprove the quality of tube through the reeling and straightening-round process.