Anodizing of AZ91D magnesium alloy using environmental friendly alkaline borate-biphthalate electrolyte

A kind of environmental friendly anodizing routine for AZ91D magnesium alloy,based on an alkaline borate-potassium acid phthalate（KAP） electrolyte,was studied.The effect of KAP on the properties of the anodized film was investigated by scanning electron microscopy（SEM）,X-ray diffraction（XRD）,energy dispersive spectrometry（EDS）,potentiodynamic polarization and electrochemical impedance spectroscopy（EIS）,respectively.The results showed that the anodizing process,surface morphology,thickness,phase structure and corrosion resistance of the anodized film were strongly dependent on the concentration of KAP.In the presence of adequate KAP,a compact and smooth anodized film with excellent corrosion resistance was obtained.

AZ91 Magnesium Alloys: Anodizing of Using Environmental Friendly Electrolytes

An anodizing process, based on environmental friendly electrolyte solutions has been studied on AZ 91 magnesium alloys by using three types of electrolytes: the first is based on sodium silicate, the second on sodium hydroxide-boric acid-borax and the third on sodium silicate- potassium hydroxide-sodium carbonate-sodium tetra borate. A pretreatment including fluoride activation was applied before the anodizing process. It was found that the anodic film thickness increases as current density or anodizing voltage increases. It is also increased with deposition time until the deposition stops due to the formation of a thick anodic film. Optimization of the anodizing conditions - current density and deposition time- was made for each electrolyte. Characterization of anodizing layer was achieved by determination of surface morphology, microstructure, phase analysis, coat thickness, adhesion and corrosion resistance. In all cases, excellent adhesion and corrosion resistance was obtained. A corrosion efficiency ranging from 94% to 97% was reached;the highest value corresponding to the third electrolyte.

The Use of Sodium Silicate as a Corrosion Inhibitor in a Saline Drilling Fluid: A Nonaggressive Option to the Environment

The function of a corrosion inhibitor in drilling mud compositions is the corrosion protection of the equipment involved in drilling operations. Many compositions involve environmentally several products such as fatty amines of high molecular weight, polyoxylated amines, amides, imidazolines, nitrogen heterocyclic products, etc. The potential advantages of the use of silicates are the effective protection of carbon steel, especially in aerated saline fluids, low costs and non-aggressive behavior to environment. Gravimetric and electrochemical tests were carried out using an aerated solution of 3.5% NaCl and the addition of sodium silicate (Na2SiO3·9H2O) as a corrosion inhibitor at concentrations of 250 to 2000 mg/L. The efficiencies of the corrosion protection of carbon steel using silicate concentrations greater than 1250 mg/L were greater than 92%.

Combating Corrosion in Transmission Pipelines in Marine Environment Using Vernomia Amydalina as Inhibitor

Pipelines are system of pipes designed to transport liquids, gases or solid/ liquid mixtures over long distances. Some are used for domestic, household and sewage purposes. Others are buried underground or submerged in water for transportation of natural oil and gas (O & G) products. In this work, the specimens had to be kept in a workable state and steps were taken to prepare each specimen: all cuts and sheared edges were ground out to prevent them from becoming sites for preferential attack. The finishing of the specimen surface with grit abrasive paper (sand paper) and rinsing of the specimens in distilled water were done. Then degreasing of specimen in acetone and air-dried were carried out. Upon drying, the specimens were immediately weighed to obtain their initial weights. Twelve specimens were used for the test as follows: 6 Aluminum (Al);and 6 mild steel (MS) samples. With a 2 M concentration of Vernomia Amydalina (VA) extract solution, the MS and Al samples were immersed in different plastic containers containing 400 ml of seawater with pH value of 7.25 with no (0%) inhibitor added to it. A 5% (400 ml) of the VA solution was poured into the measuring cylinder for each sample-Al and MS. The specimens were suspended by the strings and completely immersed in the different percentage test media. The same procedure was carried out for each of the different percentages, 10%, 15%, 20%, and 25% and a total of 12 solutions were set up. The experimental procedure used was that seawater of 7.25 pH was obtained from Abonnema water front of Rivers State. At the end of every week (168 hours), the specimens were removed from the corrosive media. Observation and recording of appearance of the specimen noting sites were done. Cleanings of specimen with white handkerchief or tissue paper were carried out and washing of specimen with distilled water, scrubbing of specimen with a soft brush and dipping the specimen into acetone after washing, it was removed to air-dry and weighed. It is observed that optimum inhibition of coupons was obtained between 15% - 25% of VA solution during the first four weeks of testing. At the fifth week the inhibitor was gradually losing its effectiveness. This means that more inhibitor need be added at regular intervals to sustain the effectiveness of the inhibitor.

Three novel dendritic chitosan derivatives for inhibiting acid corrosion of petroleum pipelines

In the process of exploration and development of oil and gas fields, the acidic environment of oil reservoir, production and transport processes cause corrosion of pipelines and equipment, resulting in huge economic losses and production safety risks. Corrosion inhibitors were widely used in oil industry because of simple operation process and economical. In this study, three environmentally friendly corrosion inhibitors were synthesized based on the natural polysaccharide chitosan. Corrosion inhibition of three dendritic chitosan derivatives (We name them BH, CH and DH) on mild steel in 1 mol/L HCl solution with natural ventilation system was evaluated by weight loss experiment, electrochemical analysis and surface morphology characterization. The experimental results showed that when the three dendritic chitosan derivatives added in the corrosive medium were 500 mg L^(−1), the corrosion inhibition efficiencies were all more than 80%. Based on quantum chemical calculation, inhibition mechanisms of three dendritic chitosan derivatives were investigated according to molecular structures. The results showed that the benzene ring, Schiff base and N atom contained in the molecule were the active centers of electron exchange, which were more likely to form a film on the carbon steel surface, thereby slowing or inhibiting corrosion. The results also predicted the corrosion inhibition effect BH > DH > CH, which was consistent with the experimental conclusion.

Study on the Corrosion inhibitor and Fog Suppressor for Chemical Pickling of Iron and Steel

A new type of corrosion inhibitor and fog suppressor composed of Nitrogen-containing alkaloid,water-soluble butadiene lower polymer, and inorganic electrolyte has been investigated by gravimetric and electrochemical method. Effects or this chemicals on pickling rate and hydrogen penetration into iron and steel material in 50～150 g/L HCI or/and H2SO4 solutions at 20～70℃ temperature were examined. The amount of acid fog escaping from the surface of air-liquid was determined by chemical titration. The results indicate that the efficiency of inhibition and suppression depends on film properties by which mean a barrier film on the interface of bare mild steel/solution or an unsolvable liquid membrane as hydrophibic effect.In present work the film-forming mechanism by in situ and chemistry-mechanics effect is also discussed.

Experimental Investigation of Inhibition Efficiency of Crocin for Chloride-Induced Corrosion of Aluminum Alloys

The use of Crocin, derived from the flowers of Crocus sativus, is investigated as corrosion inhibitor for the AA1050, AA5083, AA5754 and AA6082 aluminum alloys in chloride ions environment. Aluminum and aluminum alloys are subjected to corrosion in the aggressive environment of chlorides, so several green corrosion inhibitors, mostly of plant origin, with minimum impact on health and the environment have been examined. In this study, the inhibition efficiency of 1.25 mM Crocin in a 0.01 M NaCl corrosive solution was assessed via electrochemical corrosion techniques and gravimetric mass loss measurements of the aluminum alloys. The surface of the specimens was examined using Scanning Electron Microscopy, Energy Dispersive Spectroscopy, Stereomicroscopy and Glossiness measurements. Experimental results reveal the protective anticorrosive action of Crocin for all aluminum alloys in the sodium chloride medium.

环境友好型缓蚀剂的研究进展

本文综述了金属缓蚀剂的研究进展。近年来,随着科学技术的不断发展,金属材料的需求与日俱增,金属材料因机械强度高、耐久性好而在许多有前景的领域中都是不可或缺的。但是金属材料易腐蚀,缓蚀剂的存在可以阻滞或减缓金属的腐蚀进程。人们对可持续发展认识的不断提高,环境友好型缓蚀剂必将成为今后的发展趋势。环境友好型缓蚀剂可分为无机缓蚀剂、有机缓蚀剂,本文着重介绍了一些常用的环境友好型缓蚀剂,并对其发展前景进行了展望。

绿色气相缓蚀剂的研究进展

近年来,随着人们对健康、环保和安全等方面意识的不断提升以及相关法律法规的落实,工业上对金属制品生产和应用过程中起防护作用的气相缓蚀剂提出了更高要求,一些毒性高、对环境有影响的气相缓蚀剂受到了使用限制。因此,研发和推广新一代环保、安全的气相缓蚀剂势在必行。此外,可再生资源的开发利用是人类社会可持续发展的重要措施。源自自然界动植物的可再生资源,特别是农作物、瓜果蔬菜和林木加工废弃物等资源中含有大量天然抗氧剂、防腐剂、抑菌剂等成分,作为气相缓蚀剂开发利用的潜力很大,目前国内外研究人员已经对这类新一代绿色气相缓蚀剂开展了重点研究。概述了气相缓蚀剂的发展历程,总结了氨基酸、聚天冬氨酸、植物源化合物、植物提取物等绿色气相缓蚀剂的研究现状,并对绿色气相缓蚀剂的发展趋势进行了展望,以为其产业化应用提供必要的支持。

绿色环保型缓蚀剂的研究现状

缓蚀剂为石油、石化、电力等行业减轻或避免金属腐蚀带来的损失发挥了重要作用。随着环保意识的不断增强和社会可持续发展的要求,缓蚀剂在研发、生产、使用过程中也逐步向绿色、低碳转型,在追求更高的缓蚀效率的同时,对其安全性和环保性也提出了更高的要求。本研究结合国内外缓蚀剂的研究与应用情况,从天然原料的提取、低毒的同系物或衍生物合成、副产品的利用以及碳基纳米等新型材料的开发等方面,对绿色环保型缓蚀剂的研究开发途径进行了总结。

State of the art of synthetic threshold scale inhibitors for mineral scaling in the petroleum industry: a review

Inorganic scale deposits are a major water-related problem encountered in producing oil and gas wells. The harshness of scale deposits is dependent on the field operating conditions. Scale deposits can vary from mild scaling tendencies to extreme. In general, the scale deposit will cause a reduction in formation pores, declining productivity and eventually blockage of the wellbore and hence unexpected downtime if it is allowed to persevere. To overcome this, the productivity of an oil and gas well is ensured by handling scale deposits via removal or prevention methods. Scale prevention is the best and cost-e ective method for handling scale deposits that ensures production continuity. Inhibition through 'threshold' scale inhibitor treatment is the most common method that is proven to prevent or reduce likely deposits. This paper examines the art of synthetic scale inhibitors, in particular, threshold scale inhibitors in oil and gas production. It discusses the chemistry of those inhibitors, inhibition mechanisms, treatment methods and key properties for their applications. It also highlights the chemistry of the synthetic routes often used to produce them in the laboratory and/or industry. Finally, it highlights the environmental concerns for the applicability of threshold scale inhibitors.

环保型缓蚀剂在油气管道腐蚀防护中的应用

为了延缓油气集输管道的腐蚀速率,延长管道的使用寿命,室内以丙烯酸(AA)、顺丁烯二酸酐(MA)以及丙烯酸酯(AE)为原料,制备了一种环保型缓蚀剂HBY-2,优化了合成工艺条件,并评价了其防腐蚀效果。实验结果表明:在单体的质量分数为20%、单体配比n(AA)∶n(MA)∶n(AE)=1.2∶1.2∶1.0、引发剂加量为0.5%、反应温度为80℃、反应时间为5 h的合成条件下,制备的环保型缓蚀剂HBY-2的缓蚀效果最好。当HBY-2的加量为0.3%时,缓蚀率可以达到98.7%,腐蚀防护效果较好。在相同的实验条件下,环保型缓蚀剂HBY-2的缓蚀效果明显优于钨酸钠、钼酸钠、硫脲和咪唑啉。现场应用结果表明,油井集输管道中添加缓蚀剂HBY-2后,挂片的腐蚀速率均明显降低。研究结果认为,制备的环保型缓蚀剂HBY-2能够满足油气集输管道的腐蚀防护需求,降低管道的腐蚀速率,延长其使用寿命。

钢材用缓蚀剂研究进展

在现代工业社会中,钢材的应用是不可或缺的,因为它具有优异的机械性能、经济合理的成本,因而经常在建筑、交通、机械和化工等领域发挥着重要作用。而钢材的腐蚀问题不仅会造成直接或者间接的经济损失,而且还会导致重大的安全隐患和事故;因此,做好腐蚀防护工作对于资源合理利用与社会经济发展具有重要意义。在众多防腐措施中,添加缓蚀剂具有成本低、用量少、操作方便、见效快等特点。本文就钢材用缓蚀剂展开讨论,首先介绍了缓蚀剂的分类方式,然后介绍了有机与无机缓蚀剂的一些类别以及相应国内外研究成果,最后对未来缓蚀剂的研究方向和关注热点进行了展望。

环保型缓蚀剂在油气管道腐蚀防护中的应用

为了延缓油气集输管道的腐蚀速率,延长管道的使用寿命,实验室以丙烯酸(AA)、顺丁烯二酸酐(MA)以及丙烯酸乙酯(EA)为原料,制备了一种环保型缓蚀剂HBY-2,优化了合成工艺条件,并评价了其防腐蚀效果。实验结果表明:在单体的质量分数为20%,单体配比为AA∶MA∶EA=1.2∶1.2∶1.0,引发剂加量为0.5%,反应温度为80℃,反应时间为5 h的合成条件下,制备的环保型缓蚀剂HBY-2的缓蚀效果最好。当HBY-2的加量为0.3%,腐蚀时间为30天时,缓蚀率仍可以达到97.5%,长效腐蚀防护效果较好。在相同的实验条件下,环保型缓蚀剂HBY-2的缓蚀效果明显优于钨酸钠、钼酸钠、硫脲和咪唑啉。现场应用结果表明,油井集输管道中添加缓蚀剂HBY-2后,挂片的腐蚀速率均明显降低。研究结果认为,制备的环保型缓蚀剂HBY-2能够满足油气集输管道的腐蚀防护需求,降低管道的腐蚀速率,延长其使用寿命。

环保型缓蚀剂在化工机械设备腐蚀防护中的应用

研究了一种基于丁香籽水提取物的环保型绿色缓蚀剂,分析了其在1 mol·L^(-1)HCl溶液中对低碳钢表面的缓蚀作用。通过电化学以及表面形态学实验,考察了丁香籽水提取物的缓蚀性。使用交流阻抗法和极化法探测了该缓蚀剂电化学特性。通过扫描电子显微镜(SEM)和接触角测试,表征了未接触缓蚀剂和接触缓蚀剂金属试样的表面形貌。交流阻抗分析揭示了使用800 mg·L^(-1)丁香籽提取物,在金属浸泡2.5 h后,具有显著的缓蚀度(93%),归因于缓蚀剂在低碳钢表面的吸附。根据极化试验结果,腐蚀抑制发生在阴阳极反应。SEM结果表明,800 mg·L^(-1)丁香籽提取物引入腐蚀介质可以有效保持钢表面的光滑。通过拟合Langmuir吸附等温线,验证了单层吸附模型。因此,丁香籽提取物分子与钢表面反应,在钢表面覆盖一层单分子层,从而达到良好的缓蚀效果。

环境友好型缓蚀阻垢剂的研制与性能分析

化工生产过程中应用的冷却水循环系统,其运作主要依靠热交换器,该设备的建设材料普遍是碳钢、铜等金属类材质,该材质在长期的使用下,极易产生结垢以及金属设备受腐蚀等情况,因此为有效避免和减缓此类现象的出现,工业领域的相关人员会通过添加阻垢、缓蚀剂的形式予以应对,但是目前大部分阻垢、缓蚀剂会在使用后期对环境造成二次污染。而植物作为缓蚀阻垢剂的制备原料时,不仅分布广泛、无毒无害、支持生物降解,而且提取和研制成本均较低,极具应用价值。因此文章针对环境友好型缓蚀阻垢剂的研制与性能展开研究,将甘薯作为缓蚀阻垢剂的研制原料,详细分析并阐述其具体的研制方法以及性能。

完井液用缓蚀剂研究进展

酸性完井液提高储层渗透率,但对金属腐蚀严重,因此新型高效酸化缓蚀剂的研究迫在眉睫。文章综述了有机缓蚀剂的缓蚀作用机理,分析近年来曼尼希碱型缓蚀剂、席夫碱型缓蚀剂、咪唑啉型缓蚀剂以及植物型缓蚀剂四类缓蚀剂的研究进展,以期为后续完井液用缓蚀剂的选择、应用以及缓蚀机理探讨进行技术指导。

食用香料二糠基二硫醚的缓蚀性能研究

为了解决海上石油开采过程中出现的金属腐蚀问题以及现场处理剂材料对海洋生态环境的破环,通过静态失重法、电化学法、生物毒性以及生物降解实验评价食用香料二糠基二硫醚的缓蚀性能以及环境友好性。结果表明:二糠基二硫醚缓蚀剂的加入使N80钢在腐蚀介质中的腐蚀速率显著下降,该分子在N80钢表面形成单分子层吸附,显著地提高了N80钢腐蚀反应的活化能,使得金属发生腐蚀反应要克服更高的能量障碍,从而减缓了金属的腐蚀;二糠基二硫醚分子含有多个硫原子以及糠基,以配位键的形式与金属形成稳定的化学吸附,在金属表面形成致密吸附膜,抑制电化学腐蚀的发生,达到保护金属的目的。从生物毒性、生物降解性分析,二糠基二硫醚具有优异的环境相容性。

国内外缓蚀剂研究开发与展望

本文归纳总结了近年来缓蚀剂研究开发与应用情况,探讨了缓蚀剂的应用开发和缓蚀理论研究方面的部分成果,对缓蚀剂科学技术今后的发展趋势进行了展望。主要内容包括:(1)缓蚀剂应用技术的进步,(2)缓蚀剂作用的理论研究,(3)高效绿色缓蚀剂的开发利用,(4)气相缓蚀剂的研究与应用。

环境友好缓蚀剂的研究进展

综述了环境友好缓蚀剂的研究进展 .从缓蚀剂的分子设计、合成、复配。