第38卷第2期 2017年2月
仪器仪表学报 Chinese Journal of Scientific Instrument
Vol. 38 No. 2 Feb.2017
基于磁记忆的油气管道应力损伤检测方法研究
王国庆"，2，杨理践”，刘斌
（1.辽宁石油化工大学机械工程学院抚顺113001：2.沈阳工业大学信息科学与工程学院沈阳110870）
摘要：应力集中是油气管道损坏的关键因素，对管道安全构成重大威胁。对其进行有效检测，既可发现由应力集中引起的机械损伤亦可实现对管道早期损伤的预判。磁记忆检测技术作为一种应力检测方法得到了业界认可。从能量平衡角度出发，分别从宏观和微观的角度对应力作用下的铁磁体磁记忆信号特征进行分析，建立应力与材料磁化率及原子磁矩之间的理论关系模型。采用基于第一性原理的CASTEP软件对铁碳金属体系的磁记忆力磁耦合过程进行仿真。结果表明，铁磁体在外力作用下，体系能量将重新平衡并达到稳定状态，电子能带及态密度分布特征发生改变，导致材料磁性下降，原子磁矩及材料磁化率随应力增大呈线性减小的变化趋势。通过对含裂纹管道的磁记忆检测，验证了应力损伤磁记忆检测方法的理论分析正确性及工程应用有效性，
关键词：磁记忆；应力损伤；油气管道；原子磁矩
中图分类号：TH701
文献标识码：A
国家标准学科分类代码：430.25
Study on the testing method of oil-gas pipeline stress damage
based on magnetic memory Wang Guoqing" 2 , Yang Lijian", Liu Bin
(I. School of Mechanical Engineering, Liaoning Shihua Uniwersity, Fushun I13001, China;
2. School of Information Science and Engineering, Shenyang University of Technology, Shenyang I10870, China)
Abstract : Stress concentration is the key factor that induces the damage of oil-gas pipeline. It is a serious threat to the safe of pipeline. Effective test can both find the mechanical damage induced by stress concentration and achieve pre-judgment of early damage of pipeline. Magnetic memory technology has been widely recognized by the customers as a method of stress testing- In this paper, magnetic memory signal character of ferromagnetic material in different stress application is analyzed in the macroscopic and microcosmic range from the point of energy balance. The theory relation model between stress and susceptibility or atomic magnetic moment is build. Force magnetic coupling process of magnetic memory in Fe-C metal system is simulated by CASTEP software, which is based on first principle. The results show that feromagnetic system energy balances and achieves to stable state when the stress is applied. It also weakens the material magnetism and changes the distribution character of electron band structure and density of state. Atomic magnetic moment and susceptibility decrease linearly along with the increase of stress. Finally, magnetic memory testing experiments on pipeline contained
crack demonstrate the correctness of theory analysis and effectiveness of engineering application. Keywords; magnetic memory; stress damage; oil-gas pipeline; atomic magnetic moment
线”。我国现有在役石油天然气管道十几万公里，遍布全
1引言
油气管道作为国家能源重要的运输方式，具有高效、低耗等优势，成为国民经济和社会发展不可缺少的“生命
国20多个省市和渤海、黄海、南海等广大海域，并且每年还在新建大批油气管线，形成国民经济的血脉。由于管道具有高能高压、易燃易爆、有毒有害、连续作业、链长面广、环境复杂等特点，决定了其安全管理的重要性"。很
收稿日期：2016-08
Received Date: 2016-08
*基金项有：有数耦家重大仪表专项（2012YQ090175）、国家自然科学基金（61571308）、辽宁省教育厅科学研究（1L2016009）项目资助