共查询到18条相似文献,搜索用时 234 毫秒
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通过化学成分分析、金相检验和腐蚀产物分析等方法对P110油管腐蚀穿孔的原因进行了分析。结果表明:CO2腐蚀是造成油管腐蚀穿孔失效的主要原因。 相似文献
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某油田在巡线过程中发现输油管道有泄漏现象,通过宏观分析、化学成分分析、金相检验和腐蚀产物分析等方法,结合服役工况,对输油管道腐蚀穿孔的原因进行了分析。结果表明:环焊缝防腐补口的密封失效而导致的外层腐蚀是输油管道腐蚀穿孔的主要原因,同时土壤中的Cl-加速了腐蚀穿孔的发生。 相似文献
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某注水井油管发生腐蚀穿孔失效。通过宏观观察、化学成分分析、金相检验、能谱分析、X射线衍射分析、力学性能测试、细菌培养试验等方法对油管腐蚀穿孔失效的原因进行了分析。结果表明:硫酸盐还原菌和腐生菌的存在使溶液中SO_4~(2-)被还原成H_2S,H_2S的存在引发了油管管壁的腐蚀,从而造成了油管腐蚀穿孔。油管的腐蚀类型为垢下微生物腐蚀。 相似文献
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为了解决某天然气输送管线的腐蚀穿孔失效问题,确定造成输气管道腐蚀失效的主要因素,采用扫描电子显微镜、EDS、XRD等分析方法,对某天然气输送管线失效位置进行了宏观形貌、微观形貌、材质及腐蚀产物等的分析研究.结果表明:失效管段处于低洼易积水处,局部腐蚀及穿孔主要发生在6点钟方向.通过元素成分分析和力学性能分析,确定管线材质符合标准要求.腐蚀产物分析表明:腐蚀产物中有硫化物和碳酸盐的存在,且含量较多,管道底部积水诱发的H2S电化学腐蚀和碳酸盐的沉积结垢引起的垢下腐蚀是导致腐蚀穿孔的主要原因. 相似文献
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通过对注水井腐蚀穿孔油管进行宏观形貌、材质性能及腐蚀产物成分的分析,结合服役工况调研和油管中性点计算,对注水井P110油管外腐蚀穿孔原因进行了探讨.研究结果表明:全井深油管仅腐蚀穿孔P110油管出现明显局部腐蚀,且失效油管腐蚀形貌呈"溃疡状",同时该失效油管位于中性点以下,处于正弦屈曲状态;穿孔油管材质性能符合标准API SPEC 5CT-2011对P110钢的要求,油管外壁腐蚀产物主要为FeOOH和CaCO3.因此,P110油管在屈曲状态下与套管接触形成缝隙,而后发生缝隙腐蚀失效.腐蚀类型为吸氧腐蚀,腐蚀主控因素为缝隙效应和溶解氧含量,腐蚀机理为闭塞电池的酸化自催化效应. 相似文献
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王勇 《理化检验(物理分册)》2018,(4)
某垃圾焚烧炉投入运行17 440h后,其高铬白口铸铁炉排片发生腐蚀穿孔失效,通过宏观检验、化学成分分析、金相检验、硬度试验、扫描电镜及能谱分析等方法,分析了该炉排片腐蚀穿孔失效的原因。结果表明:机组运行时冷却风量不足,焚烧垃圾中的氯、硫等腐蚀性元素导致炉排片在铬元素偏析位置发生高温腐蚀反应,腐蚀产物在高温烟气的快速冲刷下不断脱落,使炉排片壁厚不断减薄,最后在薄弱部位发生腐蚀穿孔失效。 相似文献
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采用体视显微镜、金相显微镜、电子探针等分析测试方法对腐蚀穿孔失效的BFe10-1.6-1铜镍合金管进行失效分析。结果表明:失效管的内壁存在不同程度的划痕,且腐蚀坑内壁显微组织呈现“波纹”状,符合海水冲刷腐蚀的特征;腐蚀区的显微组织呈现“冰糖块”状,符合晶间腐蚀的特征;腐蚀坑内的泥沙沉积致使管道发生点蚀。结合船用铜镍合金管的使用工况,确认该失效管腐蚀穿孔失效的主要原因是海水冲刷腐蚀、晶间腐蚀及点蚀。 相似文献
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某Q235B钢储罐底板发生腐蚀穿孔泄漏事故。通过宏观分析、微观分析、化学成分分析、力学性能试验、金相检验等方法,对储罐底板腐蚀穿孔原因进行了分析。结果表明:储罐底板的涂层因质量较差发生鼓包后破损,在破损点发生了氧腐蚀,进而导致储罐底板腐蚀穿孔。 相似文献
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Perforation of ASTM A270 TP316L stainless steel tube, used for transportation of ozonated high purity water in a pharmaceutical plant, was discovered after 3 months in actual service. The current investigation was conducted in order to explore the root causes of failure. Various techniques including on-site investigation, emission spectroscopy, ion chromatography, radioscopy, optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, and intergranular corrosion testing were implemented for failure analysis of the tube components. The results revealed that the perforation of tube was initiated from the outer wall and extended to the inner wall by pitting corrosion. The stagnant state of chloride-containing water was the main reason for inducing such corrosion attack. The weld metal was the most susceptible to corrosion attack leading to perforation of the wall thickness, although initiation sites of pitting corrosion were also observed in the base metal. The dimensions of each pit mouth are very small, but enlarged subsurface cavities were observed. The selective dissolution of material due to galvanic effects between delta-ferrite and the austenite matrix occurred in the weld zone. It is suggested that failure prevention could be achieved by controlling the quality of the insulation system. In addition, careful control of welding conditions must be implemented during fabrication. 相似文献
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某炼油厂柴油加氢精制装置的高压临氢管道在使用过程中突然爆炸起火.对该管道的失效原因进行较详尽分析后指出:由于管道长期在H2、H2S、高温、高压等恶劣工作环境下服役,材料受到氢腐蚀导致材质劣化使管道爆裂失效.严格按照Nelson曲线选用适宜的材料可以延长管道的使用寿命. 相似文献
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This paper presents a work scheme for failure analysis of buried oil pipelines. The scheme provides answers for two main questions at least: what were the causes that made the system fail and why the system failed in the way it did. The scheme is based on five stages and the results of these stages are related to each other and consistent with the type of failure, thereby providing objective conclusions. The proposed scheme was successfully applied to a case of a buried oil pipeline whose failure was a result of external corrosion. We established the occurrence of accelerated corrosion characterized by two corrosion mechanisms: one involving iron oxides and the other, iron sulfides. Furthermore, the ductile type failure has proved to be due to leakage, which is consistent with the reported evidence. 相似文献
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Y. M. Zhang T. K. Tan Z. M. Xiao W. G. Zhang M. Z. Ariffin 《Fatigue & Fracture of Engineering Materials & Structures》2016,39(4):453-466
Corrosion is an electrochemical process in offshore pipelines where the material strength begins to decrease as corrosion advances. Numerous studies have been performed to determine the remaining strengths (failure pressure) of corroded pipelines. Currently the axial corrosions of the girth welded pipelines still leave much to be understood. This study attempted to simulate girth welded pipeline with various corroded depths and lengths in order to compare with offshore pipeline design manuals. Based on the numerical results, the influence of corrosion defects parameters on remaining strengths were investigated for girth welded pipelines. The investigation on the effect of strength mismatch revealed that in the cases of under‐matched, higher failure pressures are obtained. Comparisons of current results with B31G‐2012 and DNV‐RP‐F101 demonstrated that both codes may produce somewhat conservative predictions on the failure pressure. Furthermore, an equation was proposed to evaluate the corrosion progress across girth welded pipelines. 相似文献
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Pipeline corrosion is a major challenge facing many oil and gas industries today because of the enormous downtime associated with corrosion related failures. Fatigue stress initiation in pipelines has been attributed to corrosion defects whose growth is enhanced by cyclic loading caused by the operating pressure of the transported fluids. This work reviews the concept of oil and gas transmission pipeline failures in corrosive environment by highlighting the corrosion mechanisms, dominant stress corrosion cracking trends, hydrogen induced cracking and predominant models for burst pressure estimation. Fatigue stress failure trends of corroding pipelines were also explained whilst describing some pipeline manufacturing processes that increases the susceptibility to fatigue stress failure. Optimization framework for pipeline integrity assurance against corrosion fatigue failures was also shown to incorporate different steps that includes – strategic policy initiation, policy implementation, information analysis and reviews and implementation actions. 相似文献
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邢丽 《中国材料科技与设备》2014,(6):82-85
由于受外部环境影响以及加工原油不断劣质化,导致管体内外腐蚀日趋严重,介绍了石油化工管道腐蚀现状、腐蚀原因以及修复对策。分析了碳纤维复合材料补强修复技术对石油化工腐蚀管道修复的适用性、可行性。碳纤维补强技术在石油化工腐蚀管道的成功在线应用,表明其在管道的完整性管理和长周期运行中发挥着重要的作用。 相似文献