【摘要】：油氣管道運(yùn)輸具有高效率、低成本及安全可靠等優(yōu)點(diǎn),是能源運(yùn)輸?shù)闹匾绞�。目前全世界已建成油氣輸送管道已超過(guò)250萬(wàn)公里,而且這個(gè)數(shù)據(jù)每年仍在增長(zhǎng)。我國(guó)地域遼闊,油氣資源分布不均,油氣的管道輸送成為關(guān)乎國(guó)民經(jīng)濟(jì)和社會(huì)發(fā)展的重要產(chǎn)業(yè)。由于管道具有高能高壓、易燃易爆、有毒有害、連續(xù)作業(yè)、鏈長(zhǎng)面廣、環(huán)境復(fù)雜等特點(diǎn),決定了管道安全管理的重要性。石油天然氣輸送管道所應(yīng)用的鋼鐵材料具有良好的強(qiáng)度、硬度、塑性和韌性等機(jī)械性能以及良好的鐵磁性能,其發(fā)生破壞將經(jīng)歷由應(yīng)力集中導(dǎo)致材料屈服進(jìn)而發(fā)生塑性變形再到破壞的過(guò)程。管道在建設(shè)和使用過(guò)程中,會(huì)受到各種應(yīng)力的作用,當(dāng)管道局部存在缺陷或其他質(zhì)量問(wèn)題時(shí),將會(huì)在局部產(chǎn)生應(yīng)力集中,引起局部應(yīng)力過(guò)大,甚至導(dǎo)致管道發(fā)生塑性變形或破壞。應(yīng)力集中是威脅管道安全性的一個(gè)重要因素,由應(yīng)力集中引起的塑性變形損傷被認(rèn)為是材料的早期損傷。對(duì)管道應(yīng)力集中及塑性變形的有效檢測(cè)可以預(yù)判危害的發(fā)生,并可作為評(píng)價(jià)管道應(yīng)力集中程度的依據(jù),對(duì)保障管道安全意義重大。磁記憶檢測(cè)方法作為一種應(yīng)力檢測(cè)方法已得到行業(yè)的認(rèn)可,它具有設(shè)備簡(jiǎn)單、操作方便、可實(shí)現(xiàn)在線(xiàn)大范圍無(wú)損檢測(cè)及對(duì)設(shè)備危險(xiǎn)的早期判斷等優(yōu)點(diǎn)。但目前針對(duì)磁記憶信號(hào)形成的機(jī)理及特征尚無(wú)統(tǒng)一的定論,還不能明確在各種條件下的檢測(cè)信號(hào)特征。同時(shí)由于微弱的磁記憶信號(hào)亦受影響,對(duì)實(shí)驗(yàn)研究方法的有效性具有較高要求,很多實(shí)驗(yàn)方法具有一定局限性,不能有效說(shuō)明磁記憶現(xiàn)象的真實(shí)情況,從而導(dǎo)致該方法在一些工程應(yīng)用中的有效性受到質(zhì)疑。鐵磁材料的磁性來(lái)源于原子磁矩,決定于微觀(guān)電子體系的運(yùn)動(dòng)及相互作用狀態(tài)。本文從量子力學(xué)微觀(guān)理論出發(fā),以密度泛函理論為基礎(chǔ)建立鐵磁材料力磁耦合磁記憶效應(yīng)理論模型,通過(guò)第一性原理研究了鐵磁體系在力磁耦合過(guò)程中磁記憶信號(hào)特征,對(duì)應(yīng)力損傷的磁記憶信號(hào)特征及檢測(cè)機(jī)理進(jìn)行深入研究。通過(guò)拉伸和管道打壓實(shí)驗(yàn)對(duì)理論研究結(jié)果進(jìn)行了驗(yàn)證。并開(kāi)展了管道應(yīng)力損傷磁記憶內(nèi)檢測(cè)技術(shù)的工程應(yīng)用,對(duì)該檢測(cè)方法的工程應(yīng)用可行性和有效性進(jìn)行了研究。論文對(duì)鐵磁材料的力學(xué)和磁學(xué)特性進(jìn)行了研究,明確了鐵磁材料應(yīng)力損傷形成的微觀(guān)機(jī)理及磁性的微觀(guān)起源。以體系微觀(guān)電子密度分布函數(shù)為基礎(chǔ),建立鐵磁材料力磁效應(yīng)的量子力學(xué)密度泛函理論模型,通過(guò)第一性原理仿真軟件CASTEP計(jì)算了正常鐵磁晶體結(jié)構(gòu)和塑性變形鐵磁晶體結(jié)構(gòu)兩種鐵磁體系在不同應(yīng)力作用下的能帶結(jié)構(gòu)、電子態(tài)密度分布及原子磁矩。理論研究結(jié)果表明,鐵磁材料在單向拉伸和三向拉伸兩種應(yīng)力狀態(tài)下,隨著應(yīng)力的增大,體系能帶朝遠(yuǎn)離費(fèi)米能級(jí)方向移動(dòng),費(fèi)米能級(jí)附近的電子分布數(shù)量減少,電子自旋態(tài)密度峰值逐漸下降,體系電子自旋間的交換相互作用程度減弱,軌道電子分布局域性增強(qiáng),表明鐵磁體系的磁性在應(yīng)力作用下逐漸減弱。通過(guò)原子磁矩的計(jì)算定量分析了鐵磁體系磁記憶信號(hào)的變化特征,得到磁記憶信號(hào)隨著應(yīng)力的增大逐漸減小,應(yīng)力與磁信號(hào)間存在線(xiàn)性對(duì)應(yīng)關(guān)系。當(dāng)材料發(fā)生塑性變形時(shí),磁記憶信號(hào)發(fā)生突變,信號(hào)變化特征發(fā)生改變。塑性變形鐵磁體系的磁記憶信號(hào)隨應(yīng)力變化的斜率小于正常鐵磁體系,表明材料在發(fā)生塑性變形后力磁耦合程度減弱。設(shè)計(jì)制作了不含人工缺陷及形狀效應(yīng)的拉伸試樣和長(zhǎng)距離實(shí)驗(yàn)管道,建立了材料拉伸和管道打壓實(shí)驗(yàn)平臺(tái)。實(shí)驗(yàn)研究了鐵磁材料在單向拉伸和三向應(yīng)力狀態(tài)下的磁記憶信號(hào)特征,得到鐵磁材料的應(yīng)力與磁記憶信號(hào)的對(duì)應(yīng)關(guān)系。分析了鐵磁材料在應(yīng)力作用下由彈性變形轉(zhuǎn)變?yōu)樗苄宰冃螘r(shí),磁記憶信號(hào)的變化特征。實(shí)驗(yàn)研究表明,鐵磁材料在地磁和應(yīng)力作用下將產(chǎn)生磁記憶信號(hào),材料表面得磁感應(yīng)強(qiáng)度隨應(yīng)力的增大而減小,當(dāng)材料屈服時(shí),磁記憶信號(hào)發(fā)生突變,塑性變形后鐵磁材料力磁耦合程度減弱,磁記憶信號(hào)隨應(yīng)力變化的趨勢(shì)變緩。實(shí)驗(yàn)研究結(jié)果與理論研究結(jié)果具有一致性,驗(yàn)證了理論研究的正確性。以Φ1219輸氣管道的磁記憶應(yīng)力內(nèi)檢測(cè)為應(yīng)用背景,對(duì)油氣管道應(yīng)力損傷磁記憶內(nèi)檢測(cè)技術(shù)的工程應(yīng)用進(jìn)行研究。提出管道差異運(yùn)行壓力下的二次應(yīng)力內(nèi)檢測(cè)方法,對(duì)檢測(cè)結(jié)果進(jìn)行分析和評(píng)價(jià),對(duì)檢測(cè)到的危害點(diǎn)進(jìn)行現(xiàn)場(chǎng)開(kāi)挖驗(yàn)證。研究結(jié)果表明了油氣管道應(yīng)力損傷磁記憶內(nèi)檢測(cè)技術(shù)工程應(yīng)用的可行性和有效性。
[Abstract]:Oil and gas pipeline transportation is an important way of energy transportation because of its high efficiency, low cost, safety and reliability. At present, more than 2.5 million kilometers of oil and gas pipelines have been built all over the world, and this data is still growing every year. The importance of pipeline safety management is determined by the characteristics of high energy, high pressure, inflammable, explosive, toxic and harmful, continuous operation, wide chain and complex environment. The steel materials used in oil and gas pipelines have good mechanical properties such as strength, hardness, plasticity and toughness, and good ferromagnetism. Performance, the occurrence of failure will undergo a process from stress concentration leading to material yield and then plastic deformation to failure. Pipelines in the construction and use process, will be subjected to various stresses, when there are local defects or other quality problems in the pipeline, will produce local stress concentration, resulting in excessive local stress, or even lead to failure. Plastic deformation or failure occurs in pipelines. Stress concentration is an important factor threatening the safety of pipelines. Plastic deformation damage caused by stress concentration is considered as early damage of materials. Magnetic memory testing method as a stress testing method has been recognized by the industry. It has the advantages of simple equipment, easy operation, on-line large-scale non-destructive testing and early judgment of equipment risk. However, there is no unified conclusion on the mechanism and characteristics of magnetic memory signal formation. At the same time, because the weak magnetic memory signal is also affected, the validity of the experimental research method is highly required. Many experimental methods have certain limitations, and can not effectively explain the true situation of magnetic memory phenomenon, which leads to the method in some engineering applications. The magnetism of ferromagnetic materials originates from the magnetic moments of atoms and is determined by the motion and interaction state of the micro-electronic system. Based on the microscopic theory of quantum mechanics and the density functional theory, a theoretical model of magnetic memory effect in ferromagnetic materials with force-magnetic coupling is established. The characteristics of magnetic memory signal during the coupling process are studied. The theoretical results are verified by tensile and compression tests. The engineering application of magnetic memory inner detection technology for pipeline stress damage is carried out. The feasibility and feasibility of the method are verified. In this paper, the mechanical and magnetic properties of ferromagnetic materials are studied, and the micro-mechanism of stress damage and the micro-origin of magnetism are clarified. Based on the micro-electron density distribution function of the system, the quantum mechanical density functional theory model of ferromagnetic materials is established, and the first primitive is used. The energy band structure, electron density distribution and atomic magnetic moment of two ferromagnetic systems, normal ferromagnetic crystal structure and plastic deformed ferromagnetic crystal structure, are calculated by CASTEP. The theoretical results show that the system of ferromagnetic materials under uniaxial and triaxial tensile stress states increases with the increase of stress. The band moves away from the Fermi level, the number of electrons near the Fermi level decreases, the peak value of electron spin density decreases, the exchange interaction between electron spins decreases, and the locality of orbital electrons increases, indicating that the magnetism of the ferromagnetic system gradually weakens under stress. The variation characteristics of magnetic memory signals in ferromagnetic systems are analyzed quantitatively and numerically. It is found that the magnetic memory signals decrease with the increase of stress and there is a linear relationship between stress and magnetic signals. The slope of stress change is smaller than that of normal ferromagnetic system, which indicates that the coupling degree of force and magnetism decreases after plastic deformation. Tensile specimens and long-distance experimental pipes without artificial defects and shape effects are designed and manufactured. The experimental platform of material tension and pipe compression is established. The uniaxial tension and three-dimensional stress of ferromagnetic materials are experimentally studied. The characteristics of magnetic memory signals under stress state are obtained, and the corresponding relationship between stress and magnetic memory signals of ferromagnetic materials is obtained.The characteristics of magnetic memory signals are analyzed when ferromagnetic materials are transformed from elastic deformation to plastic deformation under stress.The experimental results show that ferromagnetic materials will produce magnetic memory signals under the action of geomagnetic and stress. The magnetic induction intensity on the surface decreases with the increase of stress. When the material yields, the magnetic memory signal mutates, the coupling degree of the ferromagnetic material weakens after plastic deformation, and the magnetic memory signal slows down with the change of stress. Based on the application background of magnetic memory stress detection in gas pipeline, the engineering application of magnetic memory stress damage detection technology in oil and gas pipeline is studied. The secondary stress detection method under differential operating pressure of pipeline is put forward, the detection results are analyzed and evaluated, and the dangerous points detected are verified by field excavation. The feasibility and effectiveness of engineering application of stress memory magnetic memory testing technology for oil and gas pipelines are presented.
【學(xué)位授予單位】：沈陽(yáng)工業(yè)大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：TE973.6

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 胡斌;沈功田;;磁記憶檢測(cè)技術(shù)在游樂(lè)設(shè)施上的應(yīng)用[J];無(wú)損檢測(cè);2016年11期

2 楊理踐;耿浩;高松巍;;長(zhǎng)輸油氣管道漏磁內(nèi)檢測(cè)技術(shù)[J];儀器儀表學(xué)報(bào);2016年08期

3 劉斌;曹陽(yáng);王國(guó)慶;;基于LAPW算法磁記憶信號(hào)相變特性的研究[J];儀器儀表學(xué)報(bào);2016年08期

4 楊理踐;王國(guó)慶;高松巍;劉斌;賈朱植;;基于OPWP算法力磁耦合磁記憶信號(hào)特征研究[J];儀器儀表學(xué)報(bào);2016年07期

5 黎敏;宋亞男;周通;徐金梧;;基于數(shù)學(xué)形態(tài)學(xué)的超聲信號(hào)盲區(qū)內(nèi)缺陷特征提取方法[J];機(jī)械工程學(xué)報(bào);2016年12期

6 SONG Wentao;XU Chunguang;PAN Qinxue;SONG Jianfeng;;Nondestructive Testing and Characterization of Residual Stress Field Using an Ultrasonic Method[J];Chinese Journal of Mechanical Engineering;2016年02期

7 閔希華;饒心;;新建油氣管道的檢測(cè)及驗(yàn)收評(píng)價(jià)技術(shù)[J];無(wú)損檢測(cè);2016年03期

8 楊理踐;王國(guó)慶;劉斌;高松巍;;油氣管道塑性變形的磁記憶檢測(cè)[J];無(wú)損檢測(cè);2016年03期

9 祝愨智;段沛夏;王紅菊;李秋揚(yáng);占傳熙;施寧;張延萍;;全球油氣管道建設(shè)現(xiàn)狀及發(fā)展趨勢(shì)[J];油氣儲(chǔ)運(yùn);2015年12期

10 邢海燕;王r，

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