导热油压力管道焊缝裂纹产生原因分析与分布规律研究  

Cause Analysis and Distribution Law of Weld ECrack in Heat Transfer Oil Pressure Pipeline

作　　者：吕钟杰 张子健 钟军平 林远龙 徐无波 徐律行 包瑜婷 LV Zhongjie;ZHANG Zijian;ZHONG Junping;LIN Yuanlong;XU Wubo;XU Lvhang;BAO Yuting(Ningbo Labor Safety and Technology Services Co.,Ltd.,Ningbo 315048,China;Ningbo Special Equipment Inspection and Research Institute,Ningbo 315048,China)

机构地区：[1]宁波市劳动安全技术服务有限公司,浙江宁波315048 [2]宁波市特种设备检验研究院,浙江宁波315048

出　　处：《电焊机》2023年第5期89-94,共6页Electric Welding Machine

基　　金：宁波市重大科技任务攻关项目(2022Z165);宁波市公益类科技计划重点项目(2022S007)。

摘　　要：在压力管道的定期检验实践中发现,导热油管道的焊缝中经常会检出裂纹,且含有裂纹的焊缝分布位置通常比较典型。采用热应力理论、挠度理论,并辅以焊缝缺陷的无损检测,对典型含缺陷管道焊缝的裂纹成因进行分析。分析得到,此类管道运行温度高,在未合理设置固定支座进行分段吸收管道热膨胀的情况下,管道将以较大的位移进行热膨胀,造成相邻两固定约束点之间的热应力过高;在走向连续改变且支撑不良的情况下,两相邻固定支座之间的中间管段因其弹性大,变形量大,其内部应力水平比其他部位管段要高;当焊口中存在未熔合、未焊透等焊接缺陷时,因几何不连续会形成明显的应力集中,缺陷的尖端极易成为裂纹源。In the practice of regular inspection of pressure pipelines,it is found that cracks are often detected in the welds of heat transfer oil pipelines,and the distribution of welds containing cracks is usually typical.In this study,thermal stress theory,deflection theory,supplemented by non-destructive testing of weld defects,are used to analyze the cracks of typical pipeline welds with defects.The analysis shows that the operating temperature of this type of pipeline is high.If the fixed support is not properly set up to absorb the thermal expansion of the pipeline in sections,the pipeline will thermally expand with a large displacement,resulting in excessive thermal stress between two adjacent fixed constraint points.High;in the case of continuous change in direction and poor support,the internal stress level of the intermediate pipe section between two adjacent fixed supports is higher than that of other pipe sections due to its large elasticity and large deformation;when there is unfused,Incomplete penetration and other welding defects,obvious stress concentration will be formed due to geometric discontinuity,and the tip of the defect can easily become the source of cracks..

关 键 词：压力管道 固定支座 热应力 焊接裂纹 分布规律 

分 类 号：TG457.6[金属学及工艺—焊接]