Gao Jie, Liang Minshuo, Wang Junqiang, Zha Sixi, Yang Ankang, Lan Huiqing
School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, China.
China Special Equipment Inspection and Research Institute (CSEI), Beijing 100029, China.
Polymers (Basel). 2025 May 18;17(10):1388. doi: 10.3390/polym17101388.
The performance of high-density polyethylene (PE) pipes joints directly affects the total pipeline's operation, and so studying the residual stress of butt fusion joints is crucial for enhancing the safety of gas pipelines. Based on a layer-by-layer ring cutting test method, we measured the distribution of residual stresses in the fusion zone and heat-affected zone of butt fusion joints for PE gas pipes. Firstly, the ring samples were cut, their diameter changes were measured, and the results were compared with those predicted by the theoretical calculations. This showed that the circumferential residual stresses of the butt fusion joint for the PE gas pipes are exponentially distributed in the base material (BM) zone, the weld zone (WZ) and the heat-affected zone (HAZ). Furthermore, the residual stresses in the HAZ are lower than those in the BM zone, and the smallest residual stresses were seen in the WZ. Finally, using X-ray diffraction (XRD) technology, the crystallinities in the BM zone, the WZ, and the HAZ of the butt joints were measured. The crystallinity gradually decreased from the WZ to the HAZ and the BM zone, and the crystallinity in each zone was also related to the magnitude of the residual stresses.
高密度聚乙烯（PE）管道接头的性能直接影响整个管道的运行，因此研究热熔对接接头的残余应力对于提高燃气管道的安全性至关重要。基于逐层环切试验方法，我们测量了PE燃气管道热熔对接接头熔合区和热影响区的残余应力分布。首先，切割环形试样，测量其直径变化，并将结果与理论计算预测值进行比较。结果表明，PE燃气管道热熔对接接头的周向残余应力在母材（BM）区、焊缝区（WZ）和热影响区（HAZ）呈指数分布。此外，热影响区的残余应力低于母材区，焊缝区的残余应力最小。最后，采用X射线衍射（XRD）技术测量了对接接头母材区、焊缝区和热影响区的结晶度。结晶度从焊缝区到热影响区和母材区逐渐降低，且各区的结晶度也与残余应力的大小有关。
