37··含缺陷燃气聚乙烯管热熔接头的力学性能实验与分析*许卫荣1谢世杰2王强2胡栋3廖晓玲4(1.湖州市特种设备检验研究院,浙江湖州313099;2.中国计量大学质量与安全工程学院,浙江杭州310018;3.泰安市特种设备检测研究院,山东泰安271099;4.杭州市特种设备检测研究院,浙江杭州310051)摘要采用拉伸试验装置对含不同工艺缺陷的HDPE管热熔接头开展拉伸试验,并结合扫描电子显微镜(SEM)对接头的断裂面形貌进行分析。研究发现:含冷焊、过焊、未熔合、卷边焊缺陷的热熔接头试样相比于正常焊接参数下的热熔接头试样,在断裂伸长率和拉伸屈服强度上都有显著降低,SEM图显示纤维之间的缠绕和银纹面积的大小是影响接头焊接性能的重要因素。结果表明:含冷焊、过焊、未熔合、卷边焊缺陷的HDPE管热熔接头的力学性能有显著降低,在长期服役过程中存在一定的安全隐患。关键词高密度聚乙烯热熔接头拉伸性能扫描电子显微镜TestingandanalysisofmechanicalpropertiesofbuttfusionjointofgaspolyethylenepipewithdefectsXUWeirong1XIEShijie2WANGQiang2HUDong3LIAOXiaoling4(1.HuzhouSpecialEquipmentInspectionandResearchInstitute,HuzhouZhejiang313099,China)AbstractTensiletestsarecarriedoutonHDPEpipehotmeltjointswithdifferentprocessdefectsusingatensiletes-tingdevice,andthefracturesurfacemorphologyofthejointswasanalyzedincombinationwithscanningelectronmicroscopy(SEM).Itwasfoundthatthehotmeltjointspecimenswithcoldwelding,overwelding,unfusedandrollededgeweldingdefectshadsignificantlylowerelongationatbreakandtensileyieldstrengthcomparedtothehotmeltjointspecimenswithnormalweldingparameters,andtheSEMimagesshowedthatthewindingbetweenfibersandthesizeofthesilverpatternareawereimportantfactorsaffectingtheweldingperformanceofthejoint.TheexperimentalresultsshowthatthemechanicalpropertiesofHDPEpipebuttfusionjointwithcoldwelding,overwelding,incom-pletefusionandedgeweldingdefectsjointaresignificantlyreduced,andtherewillbesomehiddendangersinthelong-termserviceprocess.Keywordshighdensitypolyethylenebuttfusionjointtensilepropertiesscanningelectronmicroscope0引言高密度聚乙烯(HighDensityPolyethylene,HDPE)管道具有耐腐性能良好,使用寿命长,成本低等优点,被广泛用...