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本文通过两起在用压力容器定期检验中发现的不锈钢应力腐蚀问题,分析了不锈钢应力腐蚀产生的原因,阐述了如何在压力容器定期检验中对有应力腐蚀倾向的容器作出判断。 相似文献
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本文系统介绍了压力容器应力腐主机理和失效方式,并列出了能和H2S产生应力腐蚀的和各阁下好在在役压力容器的检验中如何发现应力裂纹和可能产生应力腐蚀的部位。 相似文献
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随着我国压力容器的大型化和高温高压化,压力容器的安全事故越来越多,而应力腐蚀断裂是一个主要的原因,已占到事故总数的42%,是一种危害性很大的灾害性腐蚀。本文从应力腐蚀开裂的概念入手,分析了应力腐蚀的特点,并在设计、制造及使用等几个重点环节提出了具体的应对措施,具有积极的意义。 相似文献
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通过对应力腐蚀的特点及影响因素、裂纹形态的分析,提出避免应力腐蚀开裂的防控措施,为压力容器设计人员和制造单位提供参考。 相似文献
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压力容器和压力管道应力腐蚀开裂机理及影响因素分析 总被引:1,自引:0,他引:1
应力腐蚀开裂(SCC)是压力容器和压力管道最主要的失效模式之一。本文介绍了应力腐蚀开裂的主要机理,并对影响因素进行了分析,根据应力腐蚀开裂机理及影响因素提出了相应的防护措施。 相似文献
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压力容器抗应力腐蚀设计的讨论 总被引:5,自引:0,他引:5
本文分析了压力容器及设备在湿润硫化氢、氢氧化钠溶液和液氨介质中应力腐蚀开裂的机理和应力腐蚀开裂过程。分析了影响应力腐蚀开裂的环境因素、材料因素和应力因素。讲座了设计中的材料选择和技术要求。通过加强制造过程的管理降低残余应力,是经济有效方法之一。 相似文献
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本文通过对湿H2S应力腐蚀环境下,H2S应力腐蚀的机理及其影响H2S2腐蚀的因素的分析,结合工程实践,提出了在不同的H2S分压下的压力容器用钢的选材要求,以供工程设计中参考。 相似文献
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在石油化工装置中,应力腐蚀导致焊缝开裂是比较常见的材料破坏现象之一,特别是在锅炉、压力容器等设备上更为常见。许多研究人员对应力腐蚀的机理、应力腐蚀产生所具备的条件和环境等方面做了大量的研究。通过大量的实践和实验发现,低碳钢和低合金钢材料在苛性碱溶液、氨溶液、含H2S的溶液、 相似文献
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应力腐蚀开裂的断裂参量研究 总被引:1,自引:0,他引:1
根据焊接接头应力腐蚀开裂行为的特点,采用焊接接头力学不均匀性模拟试样,用断裂力学的 K 因子方法和 COD 方法进行研究。结果表明,焊接接头区域硬化层宽度 h 增加时,应力腐蚀裂纹扩展速率 da/dt 显著增加。 相似文献
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蒋学良 《化学工业与工程技术》2003,24(2):38-40
对发生失效破裂的炉管进行了宏观形貌分析、断口形貌分析、金相分析、有限元应力分析等 ,得出导致炉管破裂的主要原因是炉管在制造过程中产生缺陷引起的应力集中和特定的腐蚀环境共同作用下产生应力腐蚀断裂。 相似文献
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对一台煤气变换换热器管子产生的裂纹进行了原因分析,经过现场检查、金相检查、扫描电镜、电子能谱等手段进行检验,分析确认裂纹为应力腐蚀裂纹,在此基础上提出了改进措施并付诸实施,避免了应力腐蚀再次发生,提高了设备使用寿命。 相似文献
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The Dynamic Electrochemical Impedance Spectroscopy has been applied for stress corrosion cracking (SCC) investigations. The effect of applied potential and tensile stresses on the stress corrosion cracking behaviour of type 304L stainless steel (SS) immersed in 0.5 M NaCl solution of room temperature has been examined. This paper presents impedance spectra obtained for 304L stainless steel samples at the different potential values. The results obtained proved the possibility of providing new details about the dynamics of the initiation and propagation of the crack path compared to classical electrochemical techniques. 相似文献
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As a rule, stress or fatigue cracks originate from various surface imperfections, such as pits, inclusions or locations showing a residual stress. It would be very helpful for material selection to be able to predict the likelihood of environment-assisted cracking or pitting corrosion.By using Scanning Kelvin Probe (the vibrating capacitor with a spatial resolution of 80 μm) the profiling of metal electron work function (Volta potential) in air is applied to the metal surfaces showing residual stress, MnS inclusions and wearing.The Volta potential is influenced by the energy of electrons at the Fermi level and drops generally across the metal/oxide/air interfaces. Inclusions (e.g. MnS) impair continuity of the passive film that locally decreases Volta potential. The stress applied gives rise to dislocations, microcracks and vacancies in the metal and the surface oxide.The defects decrease Volta and corrosion potentials; reduce the overvoltage for processes of passivity breakdown and anodic metal dissolution. These “anodic” defects can be visualized in potential mapping that can help us to predict locations with higher risk of pitting corrosion or cracking. 相似文献
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《Journal of the European Ceramic Society》2020,40(8):2801-2810
Scheelite coating was deposited on SiC fiber tows from various liquid-phase precursors at 1100℃. Strength degradation of SiC fiber was found after fiber coating which was found to be caused by the stress corrosion as a result of gases generated from the decomposition of by-products remaining in the coating. A new and simple method of low temperature pre-heat treatment was adopted to eliminate the stress corrosion in the fiber coating process and to isolate the effect of different types of gases on the stress corrosion cracking of fibers. The tensile strength and fractography of samples with and without pre-heat treatment were compared. Furthermore, the effect of gas composition on the strength degradation of SiC fiber was also investigated through the control experiments. 相似文献