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对大型电站锅炉15Mo3低温过热器爆管进行失效分析,采用宏观分析、直读光谱仪、金相显微镜、扫描电镜、布氏硬度计、万能试验机等对低温过热器爆管失效进行化学成分、微观组织、氧化、硬度及拉伸性能分析。结果表明:爆管的化学成分满足DIN17155标准的要求;管样的抗拉强度、屈服强度、伸长率和布氏硬度分别达到459 MPa、355 MPa、30.02%和150,满足了DIN17155标准对15Mo3的要求;爆管主要原因是15Mo3材质低温过热器发生腐蚀使管壁不断减薄,最终由于强度不足而发生爆管;管壁腐蚀区域主要位于尿素喷枪下方,腐蚀的主要原因是由于尿素喷枪雾化效果不良,尿素滴落,高温下与金属反应,导致管壁持续减薄;同时对15Mo3低温过热器的安全稳定运行提出了相关的建议。 相似文献
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锅炉高温再热器使用150 000 h后发生爆管,通过对高温再爆管情况进行现场调研,并对管样进行宏观检查、力学性能试验、金相及硬度试验、壁厚及管径测量等分析。结果表明:失效管样金相组织中珠光体完全球化,碳化物已呈链状分布,从而导致其力学性能明显下降;内外壁氧化皮厚度测量结果均已超过相关标准要求。高温再热器出口联箱弯头爆管原因为:材质老化导致材料力学性能下降,材料内部产生微裂纹,由于弯头处应力较大,裂纹扩展至壁厚减薄,当壁厚减薄至不满足工况需要时,发生爆管。 相似文献
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对某燃煤火电厂锅炉屏式过热器爆管原因进行了探讨,并利用扫描电镜(SEM)、能谱(EDS)、X射线衍射仪(XRD)和金相显微镜对腐蚀产物的成分和形貌进行分析.实验结果表明:复合硫酸盐对管壁的热腐蚀,造成管壁减薄严重,与屏式过热器管子内部存在的异物共同导致过热爆管. 相似文献
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潮道明 《热处理技术与装备》2008,29(2):74-78
为探明高温高压"废热锅炉"管束爆管和严重腐蚀减薄的原因,对管束材料进行了宏观、微观金相、成分及机械性能的取样分析.其原因是由于管束在高温高压下,内壁与锅水作用,产生"泡核沸腾"腐蚀及"汽膜隔热"破坏. 相似文献
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连续油管管-管对接焊概述 总被引:1,自引:0,他引:1
在介绍连续油管(CT)材料发展的基础上,分析了CT现场管-管对接焊的技术需求和关键技术,讨论了CT管-管对接接头的性能要求,介绍了CT对接焊的国内外发展现状,提出了CT管-管对接焊技术的研究方向. 相似文献
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Separation functionals are computed for a class of manufactured object that include cylindrical and rectangular artifacts, bored tubes and parallel surfaces with variable diameter. The perfect forms applied in this analysis are spatial tubes generated from planar regular and convex polygons. The construction of the tube separation functional involves the computation of an “inner envelope” which is functionally dependent on several parameters. The inner envelope is a new construction which allows the visualization of the separation functional for a three-dimensional symmetrical artifact. Examples are used to illustrate the separation functionals associated with various manufactured artifacts. 相似文献
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简述了5454热挤压管在碳铵生产企业碳化水箱上的应用,分析了RE(稀土)在5454合金中的作用,通过对比试验评价了5454热挤压管与1060冷拉管的耐冲刷磨损性、耐腐蚀性及冷弯曲加工性。 相似文献
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Matthias Kleiner Matthias Hermes Michael Weber Herbert Olivier Grygoriy Gershteyn Friedrich-Wilhelm Bach Alexander Brosius 《Production Engineering》2007,1(1):9-17
The expansion of tubes by direct application of gas detonation waves is an alternative forming method for hollow section workpieces.
In particular the process can be used for typical hydroforming parts, for example car body or exhaust elements in automotive
industry. The gas charge of oxygen and hydrogen is both pressure medium and energy source and has the potential to cause high
forming velocities. The introduced process belongs to the category of high speed forming methods and provides typical advantages
such as higher achievable strains compared to quasi-static methods using high water pressure. Another advantage of this process
is the avoidance of high press forces by application of an “inertia-locked tool” system due to the extremely short process
time. To develop a controllable process, good knowledge of the interdependencies in the system “medium, workpiece and tool”
is essential. This can be achieved using simulations in combination with experimental investigations. The results are topic
of this paper, also including special investigations on the material behavior at high strain rates and temperature gradients.
This paper is based on investigations within the scope of a research project in the Priority Program SPP 1180, which is kindly
supported by the German Research Foundation (DFG). The investigations were carried out by cooperation of: University of Dortmund,
Institute of Forming Technology and Light-weight Construction; RWTH Aachen University, Shock Wave Laboratory; University of
Hanover, Institute of Materials Science. 相似文献