某油田井下管柱的失效分析

某油田井下管柱在维修作业中发生开裂,为了分析腐蚀失效的原因,分别从腐蚀形态、管线材质以及力学性能方面进行了研究,并有针对性地提出了建议,避免类似失效事件的再次发生.     

裂解炉管焊缝开裂原因分析

通过对裂解炉管进行宏观变形检查、力学性能分析、炉管及焊缝成分分析和显微组织分析等,确定了炉管焊缝开裂的失效原因。结果表明。炉管材质及其力学性能符合技术条件要求;炉管焊缝开裂的主要原因是由于焊丝材料选用了蠕变抗力较低的Inconel82钢,而非与管材同材质的36XS钢。而焊缝处实际使用温度较高,造成该处材料渗碳和氧化严重,降低了材料蠕变抗力也是造成焊缝开裂的原因之一。     

某厂助剂管线失效分析与建议

某厂的助剂(BFR)管线在生产过程中发生点蚀,并且在补焊过程中出现了开裂。我们从腐蚀环境、腐蚀形态、材质等方面分析了腐蚀失效发生的原因,并提出相关建议,避免类似失效事件的再次发生。     

某油田集输管线弯头开裂原因分析

某油田集输管线输送介质内含有CO_2和H_2S,这条管线的一处弯头发生了较严重的开裂失效现象。本文通过对开裂管线样品的形貌、金相和扫描电镜等进行分析,揭示了弯头开裂失效原因。弯头开裂是因为H_2S应力腐蚀破坏。     

带状组织对管材焊接性能的影响分析

由于带状组织是导致管材发生氢致开裂的重要因素,而氢致开裂是管材失效和发生事故的罪魁祸首.本文通过分析管材中带状组织的形成原因、危害及对管线钢焊接性能的影响等,为解决天然气传输管道中氢致开裂的问题提供一种思路.从带状组织的形成开始,对管材焊接后的拉伸、冲击和抗氢致开裂性能等方面进行了试验,分析了带状组织超标(3.5级)对管材环缝焊接影响.     

奥氏体不锈钢管线开裂失效分析及预防措施

某石化公司一奥氏体不锈钢管线发生腐蚀开裂。本文通过宏观检验、化学成分分析、金相检验和硬度检验等方法进行失效原因分析,确定开裂原因为碱应力腐蚀开裂,并提出了建议措施。     

BOG增压机304L管线开裂失效分析

采用光学显微镜、扫描电镜对BOG增压机304L管线失效断口形貌进行观察,并结合理化试验结果分析了BOG增压机管线开裂失效的原因。结果表明:焊接接头填充金属量多,焊接停留时间长,焊接部位热输入量过大,导致在主管上形成了焊接热裂纹,并在增压机工作时振动的影响下开裂失效。建议提高接头尺寸精度,减小热输入,焊后进行表面无损检测,确保无焊接热裂纹。     

海上某油田采油树水相出口管线腐蚀失效分析

采油树管线通常采用钢质管道,随着服役年限的增加,加上海洋腐蚀环境的复杂性和恶劣性,井口采油树不可避免会出现锈蚀、腐蚀、冲蚀等缺陷。对采油树的腐蚀失效分析是通过对材质、工况、内外腐蚀环境等因素进行研究,寻找腐蚀失效的原因,提出预防重复腐蚀失效的有效措施,避免重大损失发生。本文介绍了海上某油田采油树水相出口管线腐蚀实效分析案例,强调了施工管理、生产监督、材质的选择和施工工艺合理性的重要性,以及如何通过腐蚀失效分析提供合理的解决措施来缓解或消除腐蚀问题。     

冷却水管破裂失效分析

某涡轮试验台调试冷却水系统时,发现外管线有一轴向裂纹.通过断口分析、金相检查、成分测试等试验,对水管破裂的原因进行了分析.结果表明,外管线破裂属于低应力腐蚀疲劳失效,管材存在带状分层夹杂物缺陷是造成破裂失效的内在因素,循环水质对管壁的腐蚀作用是促使冷却水管破裂失效的外部因素,某一水压下的压力脉动和振动加速了冷却水管的失效.     

阀门螺栓断裂原因分析

对失效螺栓的断面进行宏观形貌、显微组织和表面能谱分析,并分析了螺栓的材质。该螺栓材质存在一定的缺陷,结合该螺栓所处应用环境,认为该螺栓的断裂失效是由于氯离子诱发而起的应力腐蚀开裂。还提出了预防和改进的意见。     

Analysis and estimation of the yield strength of API X70 and X80 linepipe steels by double-cycle simulation tests

In this study, the spiral piping and electric resistance welding piping was conducted on API X70 and X80 linepipe steel sheets having different microstructures, and the yield strengths of the flattened sheets were measured. A double-cycle simulation test with tension-compression-tension or compression-tension-tension for the piping and flattening processes was conducted to estimate the yield strength. The simulation test results indicated that the yield strengths of the outer or inner wall of the pipe could be estimated by combination of Swift’s equation and the Bauschinger stress parameter, and that these estimated yield strengths were well matched within a small error range with the measured yield strengths. Thus, the variations in yield strength before and after the piping could be effectively estimated using the tension/compression properties of the leveled sheets because the strength differential effect was small and the reverse flow curves were expressed by a single curve. These findings suggested that the present estimation method played an important role in controlling microstructural and manufacturing process parameters to minimize the reduction in yield strength of the linepipe steel sheets.     

基于风险的检验(RBI)技术在兰州石化公司重油催化裂化装置的应用

通过运用基于风险的检验(RBI)技术对兰州石化公司300万吨/年重油催化裂化装置的静设备和管道进行风险评估和风险排序,针对不同的设备,不同的风险等级制定了相应的检验策略,为制定装置的检修计划和长期的检修策略提供了一种科学方法。     

Finite Element Analysis of High Temperature Piping Creep for Considering the Effect of Inner Pressure and Welding Residual Stress

利用大型有限元分析软件Abaqus的多次顺次耦合功能,先对P91钢高温主蒸汽管道焊接接头焊态和焊后热处理状态进行残余应力分析, 然后采用Norton蠕变本构关系,根据P91耐热钢在625℃下焊缝、热影响区和母材的不同蠕变参数,对内压以及内压与热处理后残余应力共同作用下的接头蠕变进行有限元分析,分别得到了焊接残余应力和焊后热处理残余应力的分布规律,同时预测了在高温环境下服役105h后蠕变应变分布. 结果表明,由于高温管道的壁厚以及约束等影响, 焊后产生了较大的焊接残余应力,通过焊后热处理可以有效地降低焊接残余应力.但由于热处理残余应力的存在, 仍对高温管道焊接接头的蠕变有较大影响,并且在焊缝与热影响区的交界处存在着较大的蠕变应变.     

Investigations on the Suitability of Coated Steel Piping System for High Pressure Seawater Reverse Osmosis Application

This study deals with the investigations concerning with the suitability of coated steel piping system as an economically viable alternative to costly stainless steel piping for high pressure seawater reverse osmosis (SWRO) application. The piping system selected for investigation is a carbon steel piping coated internally and externally with thermoplastic coating (coating powder Plascoat PPA 571). The performance of thermoplastic coating was investigated by conducting SWRO pilot plant test, salt spray test, mechanical tests and testing of the coating under crevices (both in pilot plant and laboratory), and for leachable organics and inorganics (both in laboratory and pilot plant test). The testing of coating in the pilot plant resulted in the formation of some blisters on the internal surface of the pipes. The blisters were broken causing the corrosion of underneath steel. The coating showed a poor resistance to salt fog test. In general, the coating performed satisfactorily under the crevices but showed blistering on either side of the test panels. The adhesive strength of the coating was found to be poor; however, it showed good flexibility. The results of chemical analysis did not show the leaching of organic or inorganic pollutants from the coating.     

重机产品的配管设计

根据二重集团公司产品中的配管设计特点，介绍了重机产品的配管设计要求、主要技术性能参数、管子与连接件的选用、配管设计要点和配管总图中的主要技术要求等。     

实现新型微管道机器人特定功能的条件分析

新型微管道机器人利用管内流体动能作为运动的动力源,同时当机器人停下来作检查或修理工作时,流体动能通过发电装置转换为电能,并对机载蓄电池充电。本文从理论上分析了实现新型微管道机器人这两种特定功能的条件。研究指出,当流体为气体、流速的值大于8.5L(L为机器人的长度)时,微管道机器人能在管内运动,但其静止时从管内流体获得的电能很少;当流体为液体、流速的值大于0.3L时,微管道机器人能在管内运动,并且其静止时能从管内流体获得一定的电能。     

第三代AP1000核电主管道的研制

根据AP1000主管道热段的结构特点、技术难点和316LN超低碳奥氏体不锈钢的材料特性,中国二重在超大型不锈钢钢锭冶炼和浇注、大型不锈钢毛坯锻造、大直径小弯曲半径管道弯曲成型、不锈钢大直径旁通管嘴相贯线机加工和大直径不锈钢管道热处理等领域开展了重点攻关,在国际上率先研制成功AP1000主管道热段试制件,其技术指标达到国...     

Analysis and estimation of yield strength of API X80 linepipe steel pipe by low-cycle fatigue tests

In the present study, spiral piping was conducted on API X80 linepipe steel, and the outer and inner wall pipe yield strengths were measured. A low-cycle fatigue test was conducted on a leveled X80 steel sheet to simulate piping and flattening processes, and the strain hardening and Bauschinger effects, induced from different strain histories, were evaluated and combined using Swift??s equation and the Bauschinger stress parameter, respectively. By analyzing the stress-strain curves obtained from the low-cycle fatigue test, the yield strengths of the outer and inner walls were estimated to be 592 MPa and 492 MPa, respectively, which are lower by 20?C80 MPa than that of the actual pipe used. Possible reasons for measured and estimated yield strength differences could be the simulation determining procedure of the pre-strain and Bauschinger stress parameters, preposition of same strain hardening behavior depending on strain history, and pre-strain differences depending on thickness location in the steel sheet during piping.     

MICRO-MACRO DAMAGE SIMULATION OF LOW-ALLOY STEEL WELDS SUBJECT TO TYPE IV CREEP FAILURE

A simulation method for microscopic creep damage at grain boundaries in the finegrain heat-affected zone of low-alloy steel welds involving high energy piping was proposed on the basis of the combination of elastic-creep FEM (finite element method) analysis and random fracture resistance modeling of the materials. The procedure to determine the initiation and growth-driving forces of small defects were briefly described. Then, a simulation procedure combining the stress distribution from elasticcreep FEM and the random fracture resistance model was proposed, and this procedure was applied to the simulation of the microscopic damage progress in a welded joint model test and in actual power piping. The results in terms of the simulated number density of small defects throughout the wall thickness were in good agreement with the observed results.     

新型能源自给式管道机器人的原理设计与研究

管道机器人可以对管道进行低成本高效率的检测和维护。目前的管道机器人受到能源供给的限制,不能长时间远距离进行工作。本文以新型无缆管道机器人的能源供给方式为基础,详细论述了新型能源自给式管道机器人总体结构设计,发电蓄能部分结构设计、支撑轮组件的设计和导向机构设计,这些设计为建立新型能源自给式管道机器人的模型并进行速度控制奠定了基础。