Study On Numerical Simulation And Process Optimization Of High Density Polyethylene Pipe Welding

At present, because of the superior performance of high density polyethylene, the application of PE pipe is becoming more and more popular. For high density polyethylene pipe connection, welding technology is the key of the high density engineering plastic pressure pipe safety. And the temperature distribution in the welding process has a very important influence on the welding quality. So, we put forward the study of numerical simulation and process optimization of high density polyethylene pipe weldingPolyethylene pipe weld joints of one dimensional unsteady overall heat transfer model is established by MARC software and simulates temperature field and stress field distribution of the welding process, and the thermocouple temperature automatic acquisition system automatically detects the welding temperature field changes of welding temperature field, and compared the simulation results with experiment. The results show that, at the end of the heating, the temperature of the pipe does not reach the maximum, but reached the maximum at 300 s, which indicates that the latent heat of phase change in the process of pressure welding. In the process of pressure welding, the axial stress of the pipe is gradually changed from tensile stress to compressive stress.Do a post-processing for welded joint after welding, pipe will be put into a 10 ?water bath for cooling; make the pipe into the standard sample after welding, and place it in the furnace for heat treatment, eliminating the internal stress and improving the performance of the weld.Compared the mechanical properties of the processed and not dealing welding joints by bending test After that, do the XRD and scanning electron microscopy(SEM) experiments to compare the crystalline and the fracture microstructure, get the best welding technology parameters and methods.Through the above experiments we can determine the high-density polyethylene pipe temperature distribution along the axial direction, the relationship between the heating melting layer thickness and the welding parameters in the welding process; at the same time we can obtain the best method of welding through the post-processing the bending experiment.