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1.
某钢厂辐射管为退火炉的主要加热设备,在运行过程中受到严重腐蚀.本文用X光衍射分析、扫描电镜及能谱分析等手段对腐蚀产物进行分析,确定其腐蚀失效原因.结果表明:造成材料腐蚀最有害的成份为S、F、Cl、V,因此,腐蚀的主要类型是硫腐蚀、氧化,但同时存在钒腐蚀和卤族元素的腐蚀,因而腐蚀的过程是多种类型腐蚀互相影响、共同作用的结果.   相似文献   

2.
在页岩气田开发中腐蚀问题越来越受到关注,结合国内外页岩气田腐蚀情况,认为在页岩气田中以细菌腐蚀、二氧化碳腐蚀、冲刷腐蚀、沉积腐蚀为主。整理了SRB微生物腐蚀规律、SRB-CO2-Cl-协同作用和腐蚀竞争机制的特征,从防腐管理、杀菌剂、腐蚀监测及预测等方面提出防腐措施,为今后页岩气高效开发提供参考。  相似文献   

3.
采用点腐蚀测深仪观察联合站内原油处理系统、天然气处理系统和污水处理系统管道腐蚀监测挂片的点腐蚀坑形貌,测量和采集点腐蚀坑相关数据,并对点腐蚀程度进行评级,分析不同腐蚀监测环境对点腐蚀坑的影响。结果表明:油、气、水处理系统管道腐蚀挂片在平均腐蚀都为轻度的范围内,点腐蚀程度逐步加重,通过点蚀评级和孔蚀系数的深入研究,为合理评价腐蚀监测挂片的腐蚀程度,对介质腐蚀性进行有效监测提供科学的技术支撑。  相似文献   

4.
腐蚀给世界各国造成的经济损失是巨大的,为充分认识腐蚀、表征腐蚀、控制腐蚀,腐蚀科研工作者对于腐蚀监测技术探索的脚步从未停歇。针对当前腐蚀监测技术状态,本文重点从监测技术种类、监测原理、监测参数、监测技术应用优缺点等方面开展了详尽的论述,同时讨论了腐蚀监测技术在工程实际应用中存在的一些问题,并对未来腐蚀监测技术的发展做了一些展望。  相似文献   

5.
不锈钢的腐蚀分析   总被引:4,自引:0,他引:4  
分析了不锈钢应力腐蚀开裂(SCC),点腐蚀、晶间腐蚀,腐蚀疲劳,缝隙腐蚀,以及不锈钢的腐蚀机理。  相似文献   

6.
空气预热器搪瓷管在投入运行后三个月便发生腐蚀,腐蚀形貌与一般低温腐蚀有较大区别。用扫描电镜观察样品微观腐蚀形貌,用水溶性物质成分分析法测定腐蚀产物中阴离子含量,用X射线能谱分析仪分析腐蚀产物中元素成分及含量,结果表明:空气预热器搪瓷管的腐蚀为点蚀发展的全面腐蚀,含有F、S、Cl的烟气是腐蚀产生的原因,烟气中F元素破坏表面搪瓷涂层后,S、Cl元素进一步造成基体碳钢材料低温腐蚀,腐蚀产物为S、Cl含量较高的铁氧化物。  相似文献   

7.
为提高腐蚀磨损条件下耐磨钢使用寿命,通过浸泡试验、磨损试验和腐蚀磨损试验以及微观组织表征方法,研究了Ni-Cr-Mo合金化HB500级耐磨钢的耐腐蚀性能、耐磨损性能、耐腐蚀磨损性能以及表面特征,并探讨了腐蚀与磨损相互作用机理。结果显示,纯腐蚀、纯磨损以及腐蚀与磨损交互作用分别占腐蚀磨损总量的0.2%、82.9%、16.9%,表明在腐蚀条件下磨损性能恶化,磨损过程中材料表层状态发生变化使腐蚀与磨损相互促进,是产生腐蚀与磨损交互作用的主要原因,降低腐蚀与磨损的交互作用,有利于提高耐腐蚀磨损性能。  相似文献   

8.
套管腐蚀问题严重制约着中海油的发展。通过套管腐蚀调查与腐蚀机理研究发现,绥中36-1油田注水井套管普遍的存在腐蚀问题,主要为CO2腐蚀。本文针对腐蚀机理进行了模拟实验,并得出规律性结论:腐蚀速率随着温度、压力、流速增加而加快。针对套管腐蚀的主要原因,研究了套管腐蚀控制技术,并提出预防套管腐蚀的几点建议,对于油田注水井的维护具有一定的指导意义。  相似文献   

9.
为提高腐蚀磨损条件下耐磨钢使用寿命,通过浸泡试验、磨损试验和腐蚀磨损试验以及微观组织表征方法,研究了Ni-Cr-Mo合金化HB500级耐磨钢的耐腐蚀性能、耐磨损性能、耐腐蚀磨损性能以及表面特征,并探讨了腐蚀与磨损相互作用机理。结果显示,纯腐蚀、纯磨损以及腐蚀与磨损交互作用分别占腐蚀磨损总量的0.2%、82.9%、16.9%,表明在腐蚀条件下磨损性能恶化,磨损过程中材料表层状态发生变化使腐蚀与磨损相互促进,是产生腐蚀与磨损交互作用的主要原因,降低腐蚀与磨损的交互作用,有利于提高耐腐蚀磨损性能。  相似文献   

10.
用失重法、扫描电镜(SEM)、X射线能谱(EDS)及X射线能谱(Ⅺ①)对温度对SM80SS特级抗硫套管钢在CO2/H2S共存条件下的腐蚀行为进行了试验研究,结果表日月.在试验条件下,低温(40℃)时,腐蚀速率较小,腐蚀产物为FeCO3和FeS0.9,膜颗粒细小、比较致密,平均腐蚀速率较小;温度逐渐升高至100℃左右时,腐蚀产物为FeCO3和FeS0.9,膜颗粒粗大、疏松,平均腐蚀速率最大;高温(150℃)时,腐蚀速率较小,腐蚀产物为FeO(OH)和FeCO3、FeS0.9,膜颗粒较小、致密,但比低温时明显粗大,平均腐蚀速率较小;高低温时腐蚀产物都有较好的局部腐蚀阻碍作用,腐蚀形式为均匀腐蚀。  相似文献   

11.
Corrosion behaviour of magnesium alloy‐based engine parts in cooling system is an urgent fundamental issue in automotive field where magnesium alloys are increasingly used. In the present work, the corrosion behaviour of AZ91D magnesium alloys in various ethylene glycol/water solutions was studied by electrochemical measurements and immersion tests at room temperature. The surfaces of the samples after immersion tests were examined using scanning electron microscope (SEM) and X‐ray diffraction (XRD). The results showed that the corrosion rates of AZ91D magnesium alloys decreased with the increase of ethylene glycol concentration in ethylene glycol/water solutions and the corrosion process was dominated by pitting corrosion. A continuous protective film transferred from corrosion products was formed on the corroded surface after sufficient immersion duration in ethylene glycol/water solutions, which is able to heal the corrosion pits. The self‐healing behaviour inhibited the further corrosion of AZ91D magnesium alloy.  相似文献   

12.
Corrosion behaviour of magnesium in ethylene glycol   总被引:1,自引:0,他引:1  
Corrosion of magnesium engine components by coolant is an important issue in the automotive industry where magnesium alloys may be used. It is of significance to understand the corrosion behaviour of pure magnesium in ethylene glycol solutions, as this can provide a basis for developing new coolants for magnesium alloy engine blocks. In this paper, through corrosion and electrochemical tests, it was found that the corrosion rate of magnesium decreased with increasing concentration of ethylene glycol. Individual contaminants, such as NaCl, NaHCO3, Na2SO4 and NaCl can make aqueous ethylene glycol solution more corrosive to magnesium. However, in NaCl contaminated ethylene glycol, NaHCO3 and Na2SO4 showed some inhibition effect. The solution resistivity played an important role in the corrosion of magnesium in ethylene glycol solutions, and the competitive adsorption of ethylene glycol and the contaminants on the magnesium surface was also responsible for the observed corrosion behaviours. The corrosion of magnesium in ethylene glycol can be effectively inhibited by addition of fluorides that react with magnesium and form a protective film on the surface.  相似文献   

13.
The destruction of material through cavitation and corrosion in ethylene glycol-water mixes Destruction of structural parts in contact with liquids through cavitation and corrosion is the consequence of complex mechanical and corrosive stresses. In recent years, extensive research at model test beds has yielded information on the stress conditions encountered in waters. It was now intended to ascertain to what extent the destruction of material through cavitation and corrosion in ethylene glycol-water mixes differs from that in waters. For this purpose, tests have been carried out with magnetostrictive oscillators on grey cast iron and copper in water, in ethylene glycol, and in mixes of both liquids; the tests on grey cast iron were extended to solutions with inhibitor additives. It was found that the mechanical stress through cavitation is about the same in the liquids investigated. Certain differences in the destruction rate are mainly due to the high boiling point of ethylene glycol and the corrosion resistance of the material concerned. In aqueous ethylene glycol solutions as well as in water, the damage can be reduced by the addition of corrosion inhibitors.  相似文献   

14.
In this work, effects of coolant chemistry, including concentrations of chloride ions and ethylene glycol and addition of various ions, on corrosion of 3003 Al alloy were investigated by electrochemical impedance spectroscopy measurements and scanning electron microscopy characterization. In chloride‐free, ethylene glycol–water solution, a layer of Al‐alcohol film is proposed to form on the electrode surface. With the increase of ethylene glycol concentration, more Al‐alcohol film is formed, resulting in the increase in film resistance and charge‐transfer resistance. In the presence of Cl? ions, they would be involved in the film formation, decreasing the stability of the film. In 50% ethylene glycol–water solution, the threshold value of Cl? concentration for pitting initiation is within the range of 100 ppm to 0.01 M. When the ethylene glycol concentration increases to 70%, the threshold Cl? concentration for pitting is from 0.01 to 0.1 M. In 100% ethylene glycol, there is no pitting of 3003 Al alloy even at 0.1 M of Cl?. Even a trace amount of impurity cation could affect significantly the corrosion behavior of 3003 Al alloy in ethylene glycol–water solution. Addition of Zn2+ is capable of increasing the corrosion resistance of Al alloy electrode, while Cu2+ ions containing in the solution would enhance corrosion, especially pitting corrosion, of Al alloy. The effect of Mg2+ on Al alloy corrosion is only slight.  相似文献   

15.
Corrosion and failure mechanisms on an aluminum (Al) alloy by ethylene glycol base solution have been studied. Extensive crevice corrosion damage and localized scale deposition are clearly observed between the failed Al alloy surface and the rubber hose, in which the leakage of ethylene glycol‐based solution occurred under an actual operating. In addition, many micro‐cracks are found at the rubber hose which is clamped with the Al alloy. The scales on the Al surface appear to be due to the occurrence of Al corrosion, followed by the precipitation of additives of ethylene glycol‐based solution in the crevice between Al alloy and rubber hose. The mechanisms that can account for the crevice corrosion and solution leakage on the Al alloy surface are discussed.  相似文献   

16.
采用电化学试验、表面形貌观察、腐蚀产物分析等方法研究了磷酸氢二钠(DSP)和D-葡糖酸钠(GS)两种物质复配后对镁合金在50%(体积分数,下同)乙二醇型冷却液中的缓蚀作用。结果表明:DSP对AZ91D镁合金在50%乙二醇冷却液中是一种混合抑制型缓蚀剂,GS对AZ91D镁合金在50%乙二醇冷却液中没有缓蚀作用;DSP和GS之间存在缓蚀协同效应,复配后的缓蚀剂是一种以抑制阳极过程为主的混合型缓蚀剂;GS的添加量存在极值,而DSP和GS的质量浓度比达到4∶1时,即复配缓蚀剂E,其缓蚀率趋于稳定;随着复配缓蚀剂E加入量的增大,缓蚀率增大,其加入量为2.5g/L时,缓蚀率高达90%以上;复配缓蚀剂E对AZ91D镁合金起到缓蚀作用主要表现为形成了MgHPO4沉淀物,通过GS络合在镁合金表面,从而抑制了镁合金在乙二醇冷却液中的腐蚀。  相似文献   

17.
A research programme has been developed in order to investigate the corrosion behaviour of metallic materials commonly used in solar heating systems. This paper presents the results of an experimental study on copper corrosion resistance in ethylene and propylene glycol/water solutions (1:1 by volume) constituting the most common bases of heat transfer fluids. Long time gravimetric tests were carried out on electrolytic copper at 80°C, even in glycol/water solutions previously degraded at their boiling temperature or polluted with 200 ppm chlorides. Chemical compositions, semiconducting properties and morphological characteristics of all surface products were investigated by X-ray diffraction analysis, pulse photopotential technique and SEM observations, respectively. Heat transfer effects on copper corrosion and copper/6351 aluminium alloy couple efficiency were evaluated by electrochemical tests. The following results were obtained:
  • – Ethylene and propylene glycol/water solutions are low corrosive media. Nevertheless, chloride pollution and/or high temperature degradation of glycols markedly increase their aggressivity. Under all the experimental conditions, copper corrosion rates are higher in ethylene than propylene glycol solutions.
  • – In chloride-free solutions, heat transfer stimulates the cathodic reaction of the copper corrosion process.
  • – Galvanic contact between copper and aluminium alloy always causes pitting corrosion on aluminium electrodes. The severity of the pitting attack is enhanced by the presence of heat transfer conditions on copper and/or chloride ions in the solutions, particularly in ethylene glycol.
  相似文献   

18.
采用电化学方法和扫描电子显微镜研究了油酸钠对AM60镁合金在50%(体积分数)乙二醇-水溶液中的缓蚀作用。结果表明:油酸钠能抑制AM60镁合金在乙二醇-水溶液中的腐蚀,是一种阳极型缓蚀剂,随着油酸钠量的增加,缓蚀率逐渐增大;油酸钠在常温和高温下对AM60镁合金在乙二醇-水溶液中均有较好的缓蚀作用,且常温下油酸钠的缓蚀效果更好;油酸钠在AM60镁合金表面的吸附为自发过程,且符合Temkin吸附等温方程。  相似文献   

19.
监测了冷板系统模拟装置冷却液的p H和铝离子含量,分析了冷板的腐蚀形貌和腐蚀产物,研究了6063铝合金冷板在乙二醇冷却液中的腐蚀行为及导电氧化处理对6063铝合金(6063-CCO)冷板腐蚀行为的影响。结果表明:在试验时间内,冷却液的p H增大,其中试验初期增加明显,后增加缓慢,趋于稳定;铝合金基体金属腐蚀产生的铝离子进入溶液和形成沉淀之间会形成动态平衡;铝制冷板在乙二醇冷却液中的腐蚀以点蚀为主,其腐蚀速率随试验时间的增加而减小,其中试验初期,6063-CCO冷板的腐蚀速率更低,但试验后期,其腐蚀速率却更大。  相似文献   

20.
A research was carried out in order to investigate the corrosion behaviour of the metals most commonly used as construction materials for solar absorber plates. With this view, an attempt was made to test the corrosion resistance of the aluminium alloy AA 6351 (nominal composition: 1% Si, 0.6% Mg, 0.3% Mn, the balance Al) towards common uninhibited heat transfer fluids, such as ethylene and propylene glycol/water mixtures. Long time gravimetric tests consisted in up to 60 day exposures of the aluminium specimens to pure, chloride-polluted, or degraded glycol/water solutions, at the temperature of 80°C. The degradation into acidic products, experienced by heat transfer liquids in service, was simulated by keeping the ethylene and propylene glycol/water solutions at their boiling temperature for 30 days, in contact with copper. In glycol/water solutions the presence of chlorides at low concentration (200 ppm) caused the aluminium corrosion rates to increase by more than one order of magnitude, while in degraded solutions, containing 143 or 86 ppm cupric ions, corrosion rates higher than two order of magnitude with respect to pure solutions were obtained. During the gravimetric tests, pitting corrosion was observed in some cases and its extent was rated by evaluating the deepest and the average metal penetration, the pit density and the average pit size. The influence of heat transfer on the alloy AA 6351 corrosion and on the couple copper/AA 6351 efficiency was evaluated by gravimetric and electrochemical tests. Heat transfer through aluminium was found to significantly increase the aluminium alloy pitting potential. On the contrary, it stimulated the aluminium galvanic corrosion, when applied on either aluminium or copper. Under galvanic coupling conditions, the aluminium corrosion rates calculated from the average galvanic currents were a very little contribution to the gravimetric corrosion rates. This demonstrates that in low conductive solutions the risk of matching such dissimilar metals as copper and aluminium does not reside in the galvanic contact itself, but mainly in the mere presence of the noblest metal in the same solution where aluminium is immersed.  相似文献   

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