共查询到18条相似文献,搜索用时 296 毫秒
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3PE防腐蚀层联合阴极保护对管道的保护效果 总被引:1,自引:0,他引:1
采用阴极保护联合3PE防腐蚀层的方法对埋地钢质管道进行了防护。试验模拟了管道3PE防腐蚀层底漆存在、金属基体暴露、金属暴露孔处未与土壤介质接触及与土壤介质完全接触的不同情况,探讨了阴极电流与通电电位之间的关系,研究了通/断电位的负移对试样3PE防腐蚀蚀层阴极剥离的影响。结果表明,试样阴极保护电流的变化与管道3PE防腐蚀层的缺陷存在、土壤接触方式、通电电位密切相关。通/断电电位正于-0.85V(CSE)时,难以阻止试样发生腐蚀,通/断电位过度负移将造成3PE防腐蚀层的阴极剥离,使3PE防腐蚀层提前失效。 相似文献
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对西部某高强钢管道三层聚乙烯(3PE)防腐蚀层进行了现场调查,同时采用扫描电子显微镜(SEM)观察、能谱(EDS)分析、截面厚度测试等手段对典型剥离位置熔结环氧(FBE)表面进行了分析,探究了防腐蚀层失效的原因。结果表明:现场检测发现的3处防腐蚀层剥离,其中2处与防腐蚀层制备过程的控制参数相关,环氧粉末固化度不满足要求是导致剥离的主要原因,涂层的厚度和表面清洁度控制也存在一定的问题;另外1处失效与施工造成的机械损伤有关,损伤位置附近涂层在阴极保护的作用下发生剥离。 相似文献
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3PE涂层由于其稳定的高品质性能在中国管道工程上已经得到了广泛的应用,而近年来,在某些管道现场调查中发现有大面积的剥离现象,对管道安全产生较大威胁。为了找到涂层粘结失效原因,本文通过对比国内外防腐蚀层相关技术标准,从防腐蚀层结构、原材料性能指标、表面处理要求、涂装工艺要求、质量检验等五个方面讨论国内外防腐蚀层主要技术指标的差异,考察不同技术指标对3PE使用性能的影响,分析3PE防腐蚀层在使用过程中可能存在的失效原因,并对3PE使用中应注意的问题和国内3PE技术标准的指标的改进提出了建议。 相似文献
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介绍浦东天然气长输管线西线段外加电流阴极保护系统的安装与调试,由调试获得的数据表明,浦东地区长94km,口径φ500mm外防腐蚀层选用PE夹克的 越钢管,阴极保护采用外加电流的防腐蚀措施,其设计方案是合理的,进成功的。为今后上海地区长距离越野埋地钢管采用外加电流阴极保护方法提供了首例经验与资料。 相似文献
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R. Naderi 《Corrosion Science》2010,52(4):1291-1219
Protective performance and cathodic disbondment of epoxy coating pigmented with zinc aluminum phosphate (ZPA) were studied in this work. In solution, superior corrosion inhibition of ZPA extracted from EIS and electrochemical noise data was connected to deposition of a protective layer. EIS evaluation of the pigmented coatings indicated significant effect of modification of zinc phosphate on the protective performance as well as resistance to cathodic disbonding. Compared to ZPA, introduction of zinc phosphate resulted in inferior performance in cathodic disbonding test. In presence of ZPA, precipitation at disbonding front inferred from EIS data was confirmed by SEM. 相似文献
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《腐蚀工程科学与技术》2013,48(3):214-216
AbstractCyclic dip testing of coil coated architectural claddings was carried out in order to understand the mechanisms of cut edge corrosion. Thus, a number of nominally identical materials from the same manufacturer, but with varying steel thickness (and, hence, zinc to steel area ratios at the cut edge) were examined. The degree of disbondment of the organic coating from the cut edge was measured after 1000 h. For a constant thickness of zinc coating, the results demonstrate a linear relationship between the degree of coating disbondment and the thickness of the steel substrate. Further, the trend line showed a positive amount of disbondment when ex trapolated to zero thickness of steel. It is concluded that the cathodic disbondment mechanism plays an important role in the initiation of organic coating failure at the cut edge. However, the kinetics of cut edge disbondment is dominated by the anodic undermining mechanism. 相似文献
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Hossein Najafi Abdoulmajid Eslami Mohammad A. Golozar Amin Kavian Mahdi Ahmadi 《工业材料与腐蚀》2022,73(1):116-124
Coating disbondments on pipeline steels are regions with high resistivity where conventional cathodic protection (CP) could not fully protect. Therefore, in an attempt to mitigate this challenge, this study investigates the effect of pulse CP on corrosion mitigation and electrochemical conditions under a simulated coating disbondment on X-52 pipeline steel. In this regard, conventional and pulse CP of ?870 mVSCE were applied to the open mouth of a simulated coating disbondment. For pulse CP, frequencies of 1, 5, and 10 kHz were used. Results showed while the conventional CP was not able to fully protect the 20 cm simulated coating disbondment, for the pulse CP with increase in frequency from 1 to 5 kHz, and from 5 to 10 kHz, improve in CP potential protection under the simulated coating disbondment was achieved. This was accompanied by considerably lower corrosion and a more uniform pH distribution under the simulated coating disbondment. 相似文献
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