共查询到18条相似文献,搜索用时 609 毫秒
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使用电化学阻抗法及Tafel极化法在模拟低压工业锅炉炉水介质中研究了HEDP对20#碳钢的缓蚀性能,并探讨了炉水中Ca2+、Cl-以及SO42-对HEDP缓蚀性能的影响。实验结果表明:在模拟炉水介质中,当HEDP投加量为25 mg/L时,其对碳钢具有最佳的缓蚀效果;HEDP对碳钢腐蚀的抑制主要作用于阳极失电子反应,HEDP是一种以抑制阳极为主的缓蚀剂;炉水中Ca2+的存在会影响HEDP对碳钢电极的极化过程;Cl-、SO42-等侵蚀性阴离子会促进腐蚀的加剧,影响HEDP的缓蚀性能。 相似文献
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为了研究低磷酸盐—低氢氧化钠水处理工艺下侵蚀性阴离子对碳钢的腐蚀 ,通过高压釜静态试验 ,计算在不同浓度下碳钢的腐蚀速度 ,测定溶液中总铁离子浓度以及对表面的 EPMA(Electron probe microanalysis,电子探针微量分析 )分析。结果表明 :高温下 ,Cl-、SO42 -是引起碳钢腐蚀的主要原因。它们能阻碍膜的形成。随着离子浓度的增大 ,当 CCl- >0 .4m g/L 时 ,碳钢的腐蚀速率明显增加 ,蚀孔增多 ,耐蚀性能降低 相似文献
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为了研究20#碳钢材料在油田上的适用范围,采用室内静态腐蚀挂片正交实验法,模拟油田采出水腐蚀性因素对20#碳钢在油田采出水中的应用进行了探讨。根据腐蚀失重法及试片的腐蚀速率分析,利用正交实验考察ρ(Ca2+)、ρ(HCO3-)、ρ(Cl-)、温度、pH值对20#碳钢腐蚀行为的影响。结果表明,对20#碳钢腐蚀性影响的强弱程度为温度pH值ρ(Cl-)ρ(HCO3-)ρ(Ca2+)。温度对20#碳钢起主要的影响,其腐蚀速率随温度升高而升高。同时,腐蚀速率随pH值增大而降低。其次,ρ(Cl-)的增加使低碳钢腐蚀加重,ρ(Ca2+)、ρ(HCO3-)对20#碳钢也有一定程度的腐蚀作用。 相似文献
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采用旋转挂片腐蚀法,考察了常压塔顶酸性水的p H值、Cl-浓度以及缓蚀剂对腐蚀速率的影响,结合扫描电镜(SEM)、能谱仪(EDS)对挂片的形貌进行研究。结果表明:pH值在2~3时,20#碳钢腐蚀严重;p H值大于4时,20#碳钢的腐蚀速率趋于稳定;最佳缓蚀剂浓度为9 mg/L。添加缓蚀剂前后的扫面电镜(SEM)和能谱仪(EDS)分析显示,未添加缓蚀剂时,20#碳钢发生均匀腐蚀与点蚀,20#碳钢的腐蚀产物主要是Fe的氧化物,缓蚀剂有效的抑制了冷凝水中Cl-与金属结合,缓解了20#碳钢的腐蚀速率。 相似文献
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通过热重分析、电化学分析、组织结构分析等研究了油泥在原油沉积水中对Q235B碳钢腐蚀行为的影响。结果表明,油泥覆盖的Q235B碳钢在模拟沉积水中浸泡的前21 d内腐蚀速率逐渐升高,腐蚀形式以点蚀为主。浸泡21 d后Q235B碳钢的腐蚀速率下降,腐蚀形态由局部腐蚀为主转变成全面腐蚀。在腐蚀的起始阶段,油泥中含有的硫酸盐还原菌(SRB)能够诱导碳钢发生局部腐蚀。随着浸泡时间延长,腐蚀产物和油泥沉积层附着在金属表面,抑制了腐蚀反应的继续进行。 相似文献
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沧州沧井化工有限公司循环冷却水的补充水是沿海浅层地下水,Cl-的质量浓度高达540mg/L,原设计采用进口的以无机磷为主的处理药剂,使碳钢换热设备的腐蚀速率达0.3~0.4mm/a。后将补充水改为浅层地下水加少量深井水,控制补充水的ρ(Cl-)为150~300mg/L,并采用以有机磷和膦羧酸为主的水处理药剂,生产运行结果表明,在浓缩倍数为2.5~3.5的条件下,碳钢的腐蚀速率为0.06mm/a。 相似文献
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通过复配实验筛选出一种不含NO2-的复配缓蚀剂,失重法实验表明,钢、铝、铜在含缓蚀剂的乙醇冷媒液中的腐蚀速度明显降低,当缓蚀剂浓度达到1.3%时,腐蚀速度近乎为零,有效地抑制了碳钢、紫铜和铝合金材料在冷媒液中的腐蚀,同时提高了冷媒液的沸点,改善了冷媒液的稳定性。 相似文献
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H.X. Guo 《Electrochimica acta》2006,52(3):1108-1116
The erosion-enhanced corrosion of carbon steel A1045 was investigated by electrochemical methods in three borate buffer solutions with different concentrations, and the resistance of material to erosion-enhanced corrosion was discussed from the passive film growth kinetics. In polarization tests, the carbon steel exhibited comparable passive behavior in the three solutions. However, the dependence of passive current density on sand concentration became more significant with a decrease in borate concentration. The scratching simulation tests showed that after the passive film was damaged the peak current and decay constant were higher in the dilute solution, indicating a slower film growth rate. Based on point defect model (PDM), the key parameters for passive film growth are the diffusivity and density of the defects within the film. Mott-Schottky analysis in conjunction with PDM was performed and the results indicated that the diffusivities of defects were comparable in the films while the donor density increased with solution concentration. The higher donor density could result in higher diffusion flux and thus higher film growth rate, which could explain the better erosion-enhanced corrosion resistance in the concentrated solution. 相似文献
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采用线性极化法评价碳钢分浓硫酸、氢氟酸及其混酸中的腐蚀情况,讨论了不同酸性介质中温度、浓度对线性极化电阻Rp的影响规律.研究结果表明:混酸会加重碳钢的腐蚀;碳钢在70%H2SO4 20%HF中Rp最小;单组分的H2SO4、HF中,碳钢的Rp都随着温度的增加而减小;H2SO4的浓度对碳钢的腐蚀有较大的影响. 相似文献
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The use of stainless steel in high corrosion risk areas represents a viable option for reducing the life-cycle cost and extending the service life of concrete structures. However, the possible galvanic corrosion between it and carbon steel continues to be a concern. In this article, the galvanic coupling behaviours of carbon steel and three different stainless steels were investigated in simulated pore solutions and concrete specimens. The results showed that the oxygen reduction reaction was much lower on stainless steel than on passive carbon steel, leading to a lower galvanic coupling current between stainless steel and corroding carbon steel than that between passive and corroding carbon steels. However, rust contamination of stainless steel was found to increase galvanic coupling corrosion on carbon steel. 相似文献
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The changes in mechanical properties of portland cement mortars due to the addition of carbon fibres (CF) to the mix have been studied. Compression and flexural strengths have been determined in relation to the amount of fibres added to the mix, water/binder ratio, curing time and porosity. Additionally, the corrosion level of reinforcing steel bars embedded in portland cement mortars containing CF and silica fume (SF) have also been investigated and reinforcing steel corrosion rates have been determined. As a consequence of the large concentration of oxygen groups in CF surface, a good interaction between the CF and the water of the mortar paste is to be expected. A CF content of 0.5% of cement weight implies an optimum increase in flexural strength and an increase in embedded steel corrosion. 相似文献