基于仿真模拟的未焊透缺陷管道安全评价  

Safety evaluation of tube with incomplete penetration defect based on simulation

作　　者：孙贺斌 魏晓枭 李军 张兆钰 周治伊 SUN Hebin;WEI Xiaoxiao;LI Jun;ZHANG Zhaoyu;ZHOU Zhiyi(Gansu Electric Power Research Institute Technology Center Co.,Ltd.,Lanzhou 730070,China;State Grid Gansu Electric Power Company Electric Power Research Institute,Lanzhou 730070,China)

机构地区：[1]甘肃电力科学研究院技术中心有限公司,兰州730070 [2]国网甘肃省电力公司电力科学研究院,兰州730070

出　　处：《无损检测》2023年第6期62-66,共5页Nondestructive Testing

基　　金：甘肃省人力资源和社会保障厅博士后专项经费。

摘　　要：压力管道作为调相机运行中不可缺少的部件,通常采取焊接方式进行连接,因此焊接质量直接影响调相机的安全。利用Comsol仿真模拟软件对含未焊透缺陷的压力管道及其尖端裂纹应力强度因子进行计算,并结合标准GB/T 19624—2019《在用含缺陷压力容器安全评定》对焊接管道安全性给予相关评价。结果表明,未焊透缺陷深度临界尺寸为0.85 mm,安全评价指标临界数值为0.44;未焊透缺陷尖端裂纹强度因子大于管道材料门槛应力强度因子(1.98 MPa·mm^(1/2)),外载荷作用下裂纹扩展,裂纹尖端应力场强度因子KI增大;当裂纹尖端应力场强度因子达到20钢断裂韧性(30.4 MPa·mm^(1/2))时,裂纹将出现失稳扩展,造成材料的断裂。The pressure tube is a necessary accessory for the phase modifier for normal service,and which is usually connected by welding,therefore,the welding quality directly affects the safety of the phase modifier.In this paper,we calculated and analyzed the stress intensity factor of both the pressure pipe with incomplete penetration defects and its tip crack by using the Comsol simulation software.In addition,we evaluated on the safety of welded tubes based on the standard GB/T 19624—2019“Safety Assessment of Pressure Vessels with Defects in Use”.The results show that the critical dimension of the depth of incomplete penetration defect is 0.85mm,and the critical value of the safety evaluation index is 0.44.The crack intensity factor at the tip of the incomplete penetration defect is greater than the threshold stress intensity factor of the tube material(1.98MPa·mm^(1/2)).The crack expands under the action of external load,and the stress field intensity factor KIat the crack tip increases.When the stress field intensity factor at the crack tip reaches the fracture toughness of 20steel 30.4MPa·mm^(1/2),the crack will expand unsteadily,thus resulting in material fracture.

关 键 词：压力管道 未焊透 应力场强度因子 断裂韧性 安全评价 

分 类 号：TG407[金属学及工艺—焊接] TG115.28