共查询到20条相似文献,搜索用时 890 毫秒
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罗列了有关压力容器与管道失效的知识。根据大量的参考文献的研究结果,对压力容器与管道的失效原因及相关的防御措施进行了综合评述。 相似文献
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对炼油厂制氢装置低温段奥氏体不锈钢的变径管所出现的破裂失效原因进行了分析.结果表明变径管失效是应力腐蚀引起的.应力腐蚀裂纹起源于变径管焊缝内表面热影响区,变径管加工过程中所形成的不均匀粗大组织是促进应力腐蚀的主要原因. 相似文献
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某输气管线自2006年10月投产以来,至今该段管道已经发生5起管道泄漏事件,泄漏点均在管道底部.通过对失效管道的壁厚测量、理化试验、腐蚀产物分析、防腐蚀层测试,并结合施工档案,可认定该管道是由于CO2和细菌腐蚀所造成破坏.通过清管排出管道内壁中残留积水及提高输送管输天然气的洁净度,有效地降低了管道发生内腐蚀的风险. 相似文献
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LIU Tianmo FENG Dabi XIAO Changli DU Yan JIANG Hong 《材料导报》2004,18(Z3):318-319
对天然气场站计量旁通管道泄漏事故进行了失效分析,利用X-射线衍射、扫描电镜和金相等方法对管道的成分、夹杂、金相组织以及管道中的腐蚀产物进行了分析检测.结果表明:该计量旁通管道天然气泄漏是由于管道内残留的积水与天然气中的硫化氢共同作用产生腐蚀并引起管道破裂所致. 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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锅炉水冷壁爆管分析 总被引:4,自引:1,他引:3
彭国达 《理化检验(物理分册)》2003,39(11):584-586,589
锅炉水冷壁发生了钝边和无明显塑性变形爆管。通过对失效的锅炉水冷壁管进行宏观检查、化学分析和金相试验以及X射线衍射分析,发现该管向火侧外壁(烟气侧)发生了导致管壁严重减薄的高温硫腐蚀和内壁(水侧)垢下酸性腐蚀,而垢下腐蚀产物为氢原子渗入基体与Fe3C反应生成的CH4,由它引发沿晶微裂纹,最终由氢致裂纹引起管材失效。 相似文献
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The present study concerns the failure analysis of a perforated austenitic stainless steel grid, operating in a shell-and-tube heat exchanger of a petrochemical industry. Macroscopic examination of the grid indicated extensive friability and severe cracking in a direction perpendicular to its normal loading, while both grid surfaces as well as the interior of the filtration holes were covered significantly by decayed deposits. Microscopic examination of selected grid areas, after the surface deposits removal, indicated severe cracking exhibiting multiple branching, which advocates for stress corrosion cracking. Besides the extensive cracking areas, voids surrounded by twinning and slip bands were observed. Elemental microanalysis carried out in the areas around voids indicated the presence of iron and chromium at proportions that can be correlated to the formation of σ-phase. The detection of oxygen, iron and chromium within the cracks is attributed to corrosion products consisting of a mixture of iron and chromium oxides. The premature catastrophic failure of the stainless grid occurred as a synergistic effect of these distinct root-causes. Potential substitution of the currently used stainless steel with another alloy of higher resistance in stress corrosion cracking and microstructure stability at high temperatures is suggested. 相似文献
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Frequently happening drill pipe failure accidents in oil and gas wells not only affect drilling speed, but cause enormous economic losses and many safety issues. Most of these accidents are transverse cracking of drill pipe body and pin thread or axial cracking of box thread. Based on the axial cracking failures of drill pipe body in an ultra-deep well in China, this paper give a systematic analysis of axial cracking failure in consideration of service condition, material quality and stress corrosion mechanism. Measurement and inspection are performed on macroscopic and microscopic morphology of crack surface, corrosion products and circumferential residual stress. Then stress corrosion cracking experiments against hydrogen sulfide is conducted. Finally, the critical stress value for sulfide stress corrosion cracking of the drill pipe material is obtained, and the mechanisms of axial cracking failure and corresponding preventive measures are proposed. 相似文献
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In recent years intergranular stress corrosion cracking has occurred worldwide in the shrink-fitted discs of low-pressure turbine rotors made of low-alloy steels. Both anodic stress corrosion cracking and hydrogen-induced crack formation have been mentioned in the literature as possible failure mechanisms. Clarification of the role of hydrogen induced cracking was sought by carrying out a variety of tests with the low-alloy steel 26 NiCrMoV 145. The results indicate that hydrogen plays a decisive role in the failure mechanism, provided it is available in sufficiently high quantities. 相似文献
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Susceptibility of aluminium and its alloys towards hydrogen embrittlement has been well established. Still a lot of confusion
exists on the question of transport of hydrogen and its possible role in stress corrosion cracking. This paper reviews some
of the fundamental properties of hydrogen in aluminium and its alloys and its effect on mechanical properties. The importance
of hydrogen embrittlement over anodic dissolution to explain the stress corrosion cracking mechanism of these alloys is also
examined in considerable detail. The various experimental findings concerning the link between hydrogen embrittlement and
stress corrosion cracking are also discussed. 相似文献
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采用化学成分分析、硬度测试和金相检验等方法对某电厂多次发生泄漏的膨胀节进行了检测,对其形成原因进行分析。结果表明:膨胀节在服役环境下,其内侧蒸汽中携带的氯化钠,在膨胀节的波峰内侧部位发生富集和浓缩,并在工作条件下,腐蚀裂纹从膨胀节内侧启裂,以沿晶状特征逐渐向外壁延伸穿透,最终形成穿透裂纹和点蚀坑,使波峰处材质发生应力腐蚀开裂而导致泄漏。 相似文献
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A failure investigation into the root cause of fixed austenitic stainless steel climbing anchor hardware in tropical marine
climates has been presented. The incident 316L climbing anchor was fixed in a seaside limestone cliff in southern Thailand
and underwent transgranular chloride stress corrosion cracking (TGSCC) after 10 years of service. Since stainless steel does
not normally undergo stress corrosion cracking (SCC) at ambient temperatures, the conditions known to promote ambient temperature
TGSCC of austenitic stainless steel are reviewed. A mechanism that may give rise to TGSCC in limestone climbing anchors in
warm marine environments is postulated. 相似文献