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相互作用腐蚀管道剩余强度评价方法对比研究 总被引:3,自引:3,他引:0
目的分析现有腐蚀评价规范对相互影响腐蚀管道剩余强度计算的适应性,筛选合适的相互影响腐蚀管道剩余强度评价规范。方法介绍了ASME B31G—91、修正的B31G、ASME B31G—2009/2012、RSTRENG方法、DNV-RP-F101方法以及PCORRC方法等七种相邻腐蚀相互作用认定准则以及相互作用腐蚀评价方法,应用实验数据分析了各评价方法的适应性。结果 ASME B31G—91、修正的B31G、ASME B31G—2009/2012、RSTRENG方法大多以临界轴向间距为依据,超过临界轴向间距时,相邻腐蚀不发生相互影响,但未给出相邻腐蚀相互影响的评价思路或影响方式。DNV RP-F101标准明确提出了相邻腐蚀相互影响准则,并给出了相互影响腐蚀评价思路。PCORRC方法未明确给出相互影响腐蚀评价思路。结论上述七种腐蚀评价规范均以单腐蚀管道为研究基础,更适合评价单腐蚀缺陷管道,评价相互作用腐蚀缺陷过于保守,并且相邻腐蚀缺陷相互作用准则过于简单,未完全反映相邻腐蚀缺陷相互作用机理。相比而言,DNV-RP-F101方法较其他评价方法的计算结果更准确,保守性更低。 相似文献
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外腐蚀是威胁管道安全的重要因素,极易导致管道泄漏或失效断裂事故。我国长输管道全面实施完整性管理,应根据管道历史失效事件,开展管道剩余强度评价与剩余寿命预测,确定不同类型缺陷的可接受准则。阐述了国际通用的管道缺陷安全评价标准,分别是ASME B31G、修正的ASMEB31G、BS7910、DNV-RP-F101和PCORRC准则。收集不同钢级(X42-X100)含腐蚀缺陷的管道规格、缺陷特征和失效压力数据,比选上述5项评价准则的准确性。管道管理者应根据管道运行状况和缺陷特征,考虑评价准则的优缺点和适用范围,选择合理、适用的评价准则。 相似文献
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几种含体积型腐蚀缺陷管道剩余强度评价方法的特点及适用性 总被引:1,自引:0,他引:1
介绍了四种体积型腐蚀缺陷的评价方法,对比分析了其特点及适用性.结论为:ANSI/ASME-B31G适用于管材等级较低、管道服役年限长的老管道的评估,半经验、偏保守;DNV法可进行单个缺陷、相互作用的缺陷和复杂形状缺陷的评估;SY/T6151-1995法评价过程较复杂,但评价结果较准确;API RP 579-2000是目前较先进、较精确的分级评估方法,我国的SY/T6477-2000等效于它. 相似文献
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目的分析DNV-RP-F101方法评价相邻腐蚀管道失效压力的应用条件和计算方法的适应性。方法采用实验数据分析了DNV-RP-F101方法预测不同组合相互影响腐蚀管道失效数据的适应程度,应用已被实验数据验证可靠的非线性有限元数值,仿真研究了DNV-RP-F101标准的适应性。结果 DNV-RP-F101方法评价单腐蚀管道剩余强度的误差小,适应性强,作为相邻腐蚀管道失效压力评价基础合理。DNV-RP-F101方法评价相邻腐蚀管道失效压力的轴向间距限制条件设置合理,但环向角度限制应用条件远远偏离实际作用角度。DNV-RP-F101方法评价同尺寸相邻腐蚀管道失效压力整体误差在10%范围内;评价相邻腐蚀单独腐蚀长度系数之和超过某临界值后,预测值有大于真实值的趋势,评价结果存在预测风险;评价不同深度相邻腐蚀管道失效压力预测值明显高于真实值,评价结果存在预测风险,且误差范围跨度大,预测稳定性差。结论 DNV-RP-F101方法评价相互影响腐蚀管道剩余强度存在超过真实值的风险。 相似文献
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目的 提高不规则缺陷管道失效压力评估效率和预测结果的准确度。方法 采用实体有限元模型对不规则形状缺陷管道的失效压力进行了实例研究。有限元模型由1个浅腐蚀缺陷和1个深腐蚀缺陷组成,其中深腐蚀缺陷包含在浅腐蚀缺陷内。分析了深腐蚀缺陷的长度和深度对不规则形状缺陷管道失效压力的影响。根据缺陷深度剖面的不规则性,将缺陷分为3类,第1类缺陷的不规则度为1≤d/dave<1.2,该类型缺陷的轴向投影形状可以等效为矩形;第2类缺陷的不规则度为1.2≤d/dave≤1.5,该类型缺陷的轴向投影的等效形状介于矩形和抛物线之间;第3类缺陷的不规则度为1.5<d/dave,该类型缺陷的轴向投影形状可以等效为抛物线。结果 基于等效形状的有效深度和评估长度,通过改进DNV-RP-F101准则提出了一种预测不规则形状缺陷管道失效压力的新方法。该方法首先通过缺陷长度确定评估长度,然后结合不规则度和有效深度取值模型,得到该缺陷有效深度数值,最后将评估长度和有效深度引入DNV-RP-F101准则进行失效压力评估。结论 采用新的评价方法对不规则形状缺陷管道的失效压力进行了预测,结果与不同等级管道的试验结果吻合较好。文中方法的平均误差仅为1.69%,相比现有评价方法中误差最小的有效面积法,误差降低了86.37%。 相似文献
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焊接海底管道常用的两个标准是API1104(2007)和DNV-OS-F101(2007)。焊工的操作技能对于石油管线的安全至关重要,焊工资质评定是控制焊接质量的重要切入点。焊工资质评定包括重要变素、焊缝检验方法、评定范围三方面的内容,结合实际工作,对比分析了两个标准在焊工资质评定方面的差异。分析表明,评定标准在焊接方法、焊接位置的表示,接头型式,填充金属材料的分类,焊缝检验方法与验收标准,母材(包括规格尺寸)评定覆盖范围等存在着显著差异。掌握标准的要求有助于提高资质评定的有效性,保证项目施工的效率和质量。 相似文献
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一种新型酮醛胺酸化缓蚀剂的合成及性能研究 总被引:3,自引:0,他引:3
介绍了一种新型酸化缓蚀剂的合成方法、缓蚀性能,并分析了其缓蚀机理。利用酮醛胺的缩合反应,筛选最佳反应条件,合成一种曼尼希碱,在15%盐酸(90℃)中的缓蚀率达到99.74%,超过了酸化缓蚀剂评价标准SY/T54JD5-1996规定的一级水平 在90℃土酸(7.5%HCl+1.5%HF)中的缓蚀率达到99.44%,也达到了酸化缓蚀剂评价标准规定的一级水平,与碘化物、炔醇及六次甲基四胺复配后所得缓蚀剂性能超过了该标准的一级水平。 相似文献
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To estimate the pitting rate of internally corroded oil and gas gathering pipelines, a multivariate regression modelling was carried out, using pitting rates and operating parameters. These operating parameters, temperature, pH, CO2 partial pressure, water cut, wall shear stress, chloride ion concentration, sulphate ion concentration, operating pressure, oil production rate, gas production rate and water production rate, were obtained from routine monitoring of the pipelines, whereas, the pitting rates (mean pit depths over time) were determined by the ultrasonic thickness measurement technique. The operating parameters and pitting rates were also used to estimate the pit depth growth of the pipelines using Monte Carlo simulation, and field data were used to test the developed models. The results obtained indicated that the pipelines under severe pitting corrosion rate were, more conservatively predicted than those under low, moderate and high pitting corrosion rates. 相似文献
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目的 构建埋地管道腐蚀深度预测模型,预测腐蚀管道的剩余使用寿命。方法 依据ASME B31G剩余强度评价标准,给出管道的最大允许腐蚀深度计算方法,引入广义回归神经网络(GRNN),构建埋地管道腐蚀深度预测模型,采用粒子群算法(PSO)优化GRNN的网络参数,结合管道腐蚀发展趋势预测方法,对埋地薄弱管道进行腐蚀剩余寿命预测。以陕西省某埋地输油管道为例,选取8个主要外腐蚀因素,构建外腐蚀指标体系,借助Pycharm编程仿真,结合埋片试验,对该模型预测结果进行验证分析,并预测各腐蚀管段剩余使用寿命。结果 与BP模型相比,PSO-GRNN模型的管道腐蚀深度预测结果最大相对误差控制在13.77%以内,平均相对误差仅为6.63%。寿命预测结果显示,部分管段的剩余使用寿命未能达到其预期服役寿命。结论 所建模型预测性能要明显优于BP模型,预测精度更高,能够较好地预测埋地管道的最大腐蚀深度和未来的腐蚀发展规律,剩余寿命预测结果贴近实际,为管道的维修和更换提供了指导依据,在实际工程中,具有一定的应用价值。 相似文献
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Lawrence E. Eiselstein Duane Steffey Andrew Nissan Nigel Corlett Roberto Dugnani Esra Kus Sarah G. Stewart 《Journal of Materials Engineering and Performance》2009,18(5-6):768-780
ASTM F 2129 test method nor the FDA provides any guidance as to what constitutes an acceptance criterion for the corrosion resistance of implantable medical devices. Neither provide any guidance on how many samples to test or how to handle censored data, i.e. datasets where there are only a few tests that breakdown. The development of both a statistically valid acceptance criterion for corrosion resistance and a method of evaluation would be of significant benefit to the medical device community. This study of 420 nitinol cyclic polarization tests, which builds on previous research that was presented at SMST 2007, investigates the effect of long-term exposure to simulated in vivo environments with differing degrees of aeration. This was accomplished by pre-exposing electropolished (EP) nitinol to phosphate buffered saline (PBS) at 37 °C that had been sparged with either ultra high purity nitrogen or laboratory air. Immersion times ranged from 1 h up to 30 days. A total of 290 EP samples were tested in order to obtain a reasonable number of samples with breakdown, i.e. pitted. In addition, a total of 130 mechanical polished (MP) samples were also analyzed. This data allow us to test our statistical model that was presented at SMST 2007. This model takes into account the probability of breakdown per unit of exposed surface area and, if breakdown occurs, predicts the probability that E b ? E r is greater than some threshold value. Aerated PBS environments were found to have a large influence on the margin of safety against pitting in vivo. Statistical methods for treating highly right censored pitting data are presented. 相似文献
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Domínguez Adrian Sosa López René Antaño Bueno José de Jesús Pérez López Coraquetzali Magdaleno Cruz José Santos Hernández José de Jesús Coronel Dector Andres 《Protection of Metals and Physical Chemistry of Surfaces》2022,58(3):639-647
Protection of Metals and Physical Chemistry of Surfaces - The external corrosion of a pipeline buried or submerged under specific conditions was studied. The pipelines were made of API 5L X52 steel... 相似文献
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《腐蚀工程科学与技术》2013,48(4):292-296
AbstractStudies of microbiologically induced corrosion have been carried out in connection with sea water pipelines used in the oil fields of the Southern Region of Mexico. The bacteria used in the studies were obtained from a sea water pipeline belonging to a secondary oil recovery system and were grown in an API RP 38 liquid medium. The morphological and chemical characteristics of the bacteria isolated from the growth medium were investigated and phylogenetic analysis showed that the most closely related bacterial strain is clostridium sphenoides. However, the existence of significant differences in the phylogenetic codes indicates that the bacteria from the sea water pipeline belongs to a new species of sulphate reducing bacteria. Coupons of API 5L X52 pipeline steel exposed to these bacteria developed corrosion pits which did not form during the exposure of similar coupons to the sterile growth medium. What is more, bacteria from the biofilm formed on the pitted coupons contained iron, which was absent from bacteria cultured in growth medium in which there were no steel coupons. These results demonstrate the existence of an association between the new species of sulphate reducing bacteria and the development of pitting corrosion in X52 pipeline steel. 相似文献