储罐底板缺陷补焊维修后的漏磁场特征研究  

Research on the characteristics of leakage magnetic field after repair welding of tank bottom defects

作　　者：杨志军[1] 孙晗 曹怀情 杨江 高月辉 张志来 YANG Zhijun;SUN Han;CAO Huaiqing;YANG Jiang;GAO Yuehui;ZHANG Zhilai(College of Mechanical Science and Engineering,Northeast Petroleum University,Daqing 163318,China)

机构地区：[1]东北石油大学机械科学与工程学院,黑龙江大庆163318

出　　处：《压力容器》2021年第12期77-83,共7页Pressure Vessel Technology

基　　金：国家青年自然科学基金项目(51607035);国家质检总局科技计划项目(2017QK050);国家市场监督管理总局科技计划项目(2020MK138);江苏省市场监督管理局科技计划项目(KJ204126);浙江省质监系统科技计划项目(20180352)。

摘　　要：石油化工行业中,储罐底板的腐蚀缺陷时有发生,可采用补焊的方式进行维修。但在实际的漏磁检测过程中,发现补焊后的缺陷仍会产生漏磁信号,进而影响检测人员对储罐底板腐蚀情况的判断。对缺陷不同补焊表面情况以及不同补焊深度进行研究,建立了缺陷补焊维修后漏磁场三维有限元模型,得到了不同补焊表面情况以及不同补焊深度下缺陷处的漏磁场空间分布特性。在实验室条件下进行了缺陷补焊后漏磁检测试验。理论分析和试验结果表明:缺陷漏磁场大小会随着补焊深度的增加而减小;存在余高的情况下漏磁场波形图与普通缺陷漏磁场波形图趋势相反;将缺陷全部补满且表面打磨平整的情况下,可探测到的漏磁信号最小。本研究为储罐底板漏磁检测真伪缺陷判断以及储罐的补焊维修提供了参考依据。In the petrochemical industry,the corrosion defects of tank bottom plate often occur,and repair welding can be used for them.But in the actual process of MFL testing,it is found that after repair welding of the defects will still produce magnetic flux leakage signals,which influence the judgment of the inspectors on the corrosion situation of tank bottom plate.Different repair welded surface conditions and different repair welding depth of defects were studied,a three-dimensional finite element model of leakage magnetic field after repair welding maintenance was established,and the spatial distribution characteristics of leakage magnetic field at the defects under different repair welding surface conditions and different repair welding depth were obtained.The magnetic flux leakage(MFL)test after defect repair welding was carried out in laboratory.Theoretical analysis and experimental results show that the size of leakage magnetic field decreases with the increase of repair welding depth.In the case of welding scar,the magnetic field leakage waveform decreases first and then increases,which is contrary to the common defect waveform.When the defect is completely filled and the surface is polished smooth,the detectable MFL signal is minimum.This study provides a reference for judging whether the defect is true or false in the magnetic flux leakage test of tank bottom plate and the repair welding of tank.

关 键 词：储罐底板 腐蚀缺陷 补焊 漏磁检测 有限元分析 

分 类 号：TH49[机械工程—机械制造及自动化] TG115.28[金属学及工艺—物理冶金]