1-Hydroxyethylidene-1,1-diphosphonic Acid (HEDP) as a Corrosion Inhibitor of AISI 304 Stainless Steel in a Medium Containing Chloride and Sulfide Ions in the Presence of Different Metallic Cations

The novelty of this paper is the analysis in a medium containing sulfide ion due to the generation of this ion in petroleum industries, in the refining stage (the sulfide ion is also present on the produced water). The performance of 1-hydroxyethylidene-1,1-diphosphonic acid inhibitor (HEDP) was investigated by potentiodynamic polarization, electrochemical impedance spectroscopy, and weight loss measurements in a dissolution of AISI 304 stainless steel immersed in a solution containing chloride and sulfide ions. The protection of the stainless was increased with the addition of divalent cations (Ca2+, Zn2+, and Mg2+). Potentiodynamic polarization studies have shown that the inhibitor alone has anodic protection, but the addition of Ca2+ (10 mg·L-1) favors the cathodic protection, and the addition of Zn2+ (20 mg·L-1) and Mg2+ (10 mg·L-1) mixed-type is observed. Electrochemical impedance spectroscopy was performed at three distinct potentials: -0.3 [V vs. SCE], Ecorr [V vs. SCE], and 0.1 [V vs. SCE]. This revealed that calcium is responsible for favoring the formation of the film and the other elements (zinc and magnesium) favor the stabilization of the protective film. Scanning electron microscopy analysis revealed that the addition of cations provided the adsorption of HEDP on the metal surface. Weight loss results showed that the presence of zinc in a solution containing HEDP favored greater inhibitor efficiency (Zn2+ ηm = 85.2% and for Mg2+ ηm = 70.4%).

The Effect of Mix-Design and Corrosion Inhibitors on the Durability of Concrete

The deterioration of concrete over time is the result of various mechanical, physical, chemical and biological processes, with the corrosion of reinforcement being the most serious problem of durability of reinforced concrete structures. Over the last 50 years, a tremendous effort has been spent by the international scientific community with laboratory research and experimental field studies in order to increase the resistance of concrete over corrosion. This paper presents an experimental study of the corrosion behavior of 5 different concrete mix designs. The compositions were developed as per the latest concrete regulations and International Standards which are as follows: conventional concrete C30/37, conventional concrete with corrosion inhibitor as an additive, conventional concrete with surface spray sealant, fine aggregate concrete and self-compacting concrete. Their behavior against corrosion was determined via the following tests: water absorption test, water permeability test, mercury intrusion porosimetry, rapid chloride penetration test (RCPT), and accelerated carbonation test. The experimental results showed that the corrosion systems examined in the study provide anti-corrosion protection on steel rebars against corrosion comparing with the reference group. Also, an inversely proportional relationship of the water/cement ratio of a composition with its corrosion behavior was observed. Smaller w/c values (0.4 instead of 0.5) lead to better anti-corrosion resistance. In addition, an analogous relationship between the cement content of a composition and its corrosion behavior was observed.

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.

5-methyl-1H-benzotriazole as potential corrosion inhibitor for electrochemical-mechanical planarization of copper

According to the electrochemical analysis, the corrosion inhibition efficiency of 5-methyl-lH-benzotriazole （m-BTA） is higher than that of benzotrizaole （BTA）. The inhibition capability of the m-BTA passive film formed in hydroxyethylidenediphosphonic acid （HEDP） electrolyte containing both m-BTA and chloride ions is superior to that formed in m-BTA-alone electrolyte, even at a high anodic potential. The results of electrical impedance spectroscopy, nano-scratch experiments and energy dispersive analysis of X-ray （EDAX） indicate that the enhancement of m-BTA inhibition capability may be due to the increasing thickness of passive film. Furthermore, X-ray photoelectron spectrometry （XPS） analysis indicates that the increase in passive film thickness can be attributed to the incorporation of C1 into the m-BTA passive film and the formation of [Cu（I）CI（rn-BTA）], polymer film on Cu surface. Therefore, the introduction of C1- into m-BTA-containing HEDP electrolyte is effective to enhance the passivation capability of m-BTA passive film, thus extending the operating potential window.

Effect of Organic Coating Corrosion Inhibitor on Protection of Reinforced Mortar

Corrosion of reinforced concrete is the most important cause of concrete structure deterioration. In the present study, the protective effect of the reinforcement mortars against corrosion is examined. In particular, the chloride penetration resistance on reinforced cement mortars using organic coating as additive containing was studied. The aforementioned additive consists of corrosion inhibitor for protection of steel rebars against pitting corrosion. For the experimental procedure, four (4) different types of reinforced mortars were prepared. The corrosion protection of the additive was evaluated by electrochemical methods, (linear polarization resistance, Half-cell Potential Resistance and Electrochemical Impedance Spectroscopy). In addition, the mass loss of steel rebars against time of partially immersed in NaCl solution was carried out in the lab. The experimental results showed that in all examined cases the organic coating provides anticorrosion protection on steel rebars against chlorides.

Corrosion Behavior of Reinforcement Steel Embedded in Cement Mortars Using Different Protection Systems

Although reinforced concrete structures are able to withstand towards a variety of adverse environmental conditions, reinforcement corrosion could lead to concrete structure deterioration. The present study examines four different ways of using corrosion inhibitors against pitting corrosion. In particular, it was investigated the chloride penetration resistance of reinforced cement mortars using corrosion inhibitor applied in three different ways. The corrosion behavior of the specimens was evaluated by electrochemical methods such as Linear Polarization Resistance and Halfcell Potential Resistance. In addition, the mass loss of steel rebars against time of partially immersion in sodium chloride (NaCl) solution was carried out in the lab. The experimental results showed that the corrosion systems examined in the study provide anticorrosion protection on steel rebars against chlorides comparing with the reference group.

LDHs-BTA的制备及其对钢筋的阻锈性能

采用焙烧-还原法制备了苯并三唑改性水滑石(LDHs-BTA)并对其进行了表征,同时通过电化学阻抗谱测试和氯离子吸附试验探究了LDHs-BTA对钢筋的阻锈性能.结果表明:LDHs-BTA能够有效提升模拟混凝土孔隙溶液中钢筋的耐腐蚀性能;LDHs-BTA通过层间BTA^(-)与Cl^(-)之间的离子交换,实现了对Cl^(-)的吸附,其吸附过程符合Langmuir吸附模型,最大吸附量为308.41 mg/g;当LDHs-BTA掺量为0.5%时,钢筋锈蚀的临界Cl^(-)浓度显著增大,从0.02 mol/L提升至0.10 mol/L.

木质素磺酸钠衍生物对钢筋的阻锈作用研究

钢筋混凝土结构往往因钢筋锈蚀而发生过早破坏,加入阻锈剂可以有效抑制钢筋腐蚀,提高钢筋混凝土结构的耐久性。木质素磺酸盐作为一种绿色高效组分,具有良好的阻锈性能,但其减水效果较差,单独使用无法满足现代混凝土大流动度和高强度技术需求。为此,对木质素磺酸钠进行羟基、羧基接枝改性,合成了木质素磺酸钠衍生物,并将其掺入模拟孔溶液和水泥砂浆中,研究其对钢筋的阻锈作用。结果表明:模拟碱性氯盐环境和砂浆加速腐蚀环境下,木质素磺酸钠衍生物均可增大电荷转移电阻以及减小腐蚀电流密度,起到显著的阻锈作用;在水灰比为0.35时,掺入木质素磺酸钠衍生物的水泥净浆流动度可达350 mm,减水效果接近聚羧酸,可满足混凝土的流动性和强度需求。

木质素磺酸钙对模拟混凝土孔隙腐蚀液中碳钢阻锈作用

钢筋混凝土结构常因钢筋锈蚀而导致过早破坏,加入阻锈剂可以有效抑制钢筋锈蚀,提高钢筋混凝土结构耐久性。在模拟混凝土孔隙腐蚀液中加入不同浓度的木质素磺酸钙,通过开路电位、交流阻抗谱和动电位极化曲线研究其对碳钢的阻锈作用与机理。结果表明:在3.5%Na Cl、p H为12.5的腐蚀液中,木质素磺酸钙可提高开路电位、增大电荷转移电阻以及减小腐蚀电流密度,从而起到阻锈作用。同时,木质素磺酸钙在碳钢表面能够与氯离子竞争吸附,保护钝化膜,抑制腐蚀发展。

维生素在含氯混凝土模拟孔隙液中对钢筋的缓蚀作用

为研究钢筋混凝土体系中维生素缓蚀剂的缓蚀作用,本文采用动电位极化和电化学阻抗谱测试,研究了硫胺素(VitB1)、烟酸(VitB3)、吡哆醇(VitB6)和抗坏血酸(VitC)在含氯混凝土模拟孔隙液中对钢筋的缓蚀作用,并基于密度泛函理论进行了量子化学计算,讨论了维生素对钢筋的缓蚀机理。结果表明,在含0.05 mol/L NaCl的混凝土模拟孔隙液中,VitB6的缓蚀效果最好,因为其最高占据分子轨道和Fe 3d轨道间的键合稳定性最强。每种维生素都存在一个达到最佳缓蚀率IE的特定浓度添加值,此时VitB1和VitB3表现为阳极型缓蚀剂,VitB6和VitC为混合型缓蚀剂。随着维生素浓度的增加,IE出现反向波动的趋势,这是由于缓蚀剂的极性基团吸附于钢筋表面,抑制了阴极反应,进一步加剧了阴、阳极间的不平衡。

基于包覆性钡盐的混凝土防腐剂性能研究

采用碱性纳米二氧化硅分散液对钡盐进行包覆性处理,基于三种钡盐(氢氧化钡、碳酸钡、硝酸钡)配制盐卤腐蚀抑制剂,与未包覆钡盐类盐卤腐蚀抑制剂进行对比,研究包覆性钡盐盐卤腐蚀抑制剂的抗蚀系数、28d抗压强度比和氯离子扩散系数。结果表明,包覆性钡盐盐卤腐蚀抑制剂可显著提高混凝土的耐蚀性能,其90d抗蚀系数高达1.189,28d抗压强度比高达111.11%,氯离子扩散系数低至2.50×10^(-12)m^(2)/s。

阻锈剂在海洋工程高性能混凝土中的研究进展

从海洋工程混凝土结构耐久性和腐蚀的影响因素出发,分析了混凝土钢筋锈蚀的原因和阻锈剂的作用机理,并详细介绍国内外阻锈剂的发展概况以及无机阻锈剂和有机阻锈剂的研究现状。同时,就阻锈剂的评价方法和发展趋势进行了总结。

迁移型阻锈剂在钢筋混凝土中的研究进展

钢筋锈蚀导致混凝土耐久性的降低问题一直受到全世界的广泛关注,迁移型有机阻锈剂可以有效提升混凝土的耐久性,并与混凝土结构有着很好的相容性,且在经济上优于普通掺入型无机阻锈剂。从混凝土工程钢筋锈蚀原因、迁移型阻锈剂的阻锈机理进行分析,进而介绍迁移型阻锈剂的国内外研究情况以及迁移型阻锈剂的性能试验和评价方法,最后就迁移型阻锈剂相关应用的问题进行总结。

迁移型阻锈剂对混凝土钢筋的保护作用

氯离子诱发的钢筋锈蚀是影响混凝土结构耐久性的主要因素之一。利用电化学和表面分析技术研究了有机类表面迁移型阻锈剂在混凝土腐蚀模拟液中对混凝土块及其中钢筋的保护作用。结果表明:新型阻锈剂的缓蚀效率超过80%;加入新型阻锈剂后,钢筋表面平整;涂刷在混凝土表面的复合阻锈剂,能够迁移到混凝土内部,通过物理、化学吸附,在钢筋表面形成一层吸附膜,阻碍了氯离子与钢筋表面的接触,使腐蚀反应速率降低,从而起到了保护钢筋的作用。

火电厂铜合金凝汽器氯离子腐蚀及缓蚀剂研究综述

目前我国火力发电厂凝汽器材质以铜合金为主,而氯离子对铜合金凝汽器的腐蚀是火电厂循环冷却水系统的主要腐蚀性因素,直接关系到生产的安全运行。作者首先针对铜合金材质氯离子腐蚀评价方法及腐蚀机理进行了综述,然后对该类缓蚀剂的研究进展进行了系统归纳,涉及BTA及其衍生物以及MBT的论述,亦包括了其他唑类及非唑类缓蚀剂情况,同时对部分缓蚀剂的腐蚀控制机理进行了描述,旨在对铜合金材质氯离子的腐蚀及控制的现状及发展方向有一个系统的把握。

SiC_P含量及缓蚀剂对SiC_P/Al金属基复合材料腐蚀行为的影响

研究了ZL101A铝合金及以其为基体含5vol%,10vol%,15vol%和20vol%SiCP的SiCP/Al金属基复合材料在3.5%NaCl溶液中的腐蚀行为,通过添加钼酸钠、硅酸钠等缓蚀剂在3.5%NaCl溶液中,将SiCP/Al金属基复合材料在室温下浸泡一定的周期,采用失重法和SEM技术分别计算腐蚀速率和分析腐蚀后的微观组织形貌。试验结果表明:SiCP颗粒增强物的加入对SiCP/Al金属基复合材料腐蚀速率影响不大,甚至略有降低,SiCP改变了铝合金基体表面腐蚀的形核和发展,点蚀数量增加、深度变浅。添加缓蚀剂后,抑制了SiCP/Al金属基复合材料表面点蚀的形成,与钼酸钠缓蚀剂相比,硅酸钠具有良好的缓蚀作用,当SiCP颗粒增强物的含量达到15vol%和20vol%时,缓蚀剂的缓蚀效果明显下降。

氯化钠对曼尼希碱型盐酸缓蚀剂缓蚀性能的影响

研究一种曼尼希碱盐酸缓蚀剂,在不同氯化钠含量的工业盐酸介质、不同温度、盐酸浓度以及缓蚀剂加量的条件下,通过失重法和电化学法测试了上述条件对曼尼希碱盐酸缓蚀剂缓蚀性能的影响,并对曼尼希碱盐酸缓蚀剂缓蚀机理和产生影响的原因进行了初步探讨。研究表明,盐酸介质中氯化钠含量对曼尼希碱盐酸缓蚀剂有一定影响,且随着氯化钠含量的增加,钢片的腐蚀速率升高。海上油田酸化施工海水配制酸液时,应考虑氯化钠对曼尼希碱盐酸缓蚀剂的影响。井下温度以及酸液浓度同样会影响缓蚀剂的缓蚀性能,可适当增加缓蚀剂的加量以达到降低腐蚀速率的效果。

迁移性阻锈剂——钢筋混凝土阻锈剂的新发展

介绍了钢筋混凝土阻锈剂的基本概念和发展背景 ,比较讨论了新发展起来的迁移性阻锈剂与传统的亚硝酸盐阻锈剂性能特点 .根据作者对迁移性阻锈剂的电化学测试和文献资料中的研究结果 ,着重分析了迁移性阻锈剂对钢筋电化学性能的影响和阻锈机理 。

缓蚀剂钼酸盐插层水滑石对Cl^-吸附行为的研究

以缓蚀剂钼酸盐插层水滑石(HT-MoO42-)为吸附剂,对NaCl溶液中的Cl-进行吸附,探讨了吸附时间、温度和Cl-初始浓度等因素对吸附的影响。测定了HT-MoO42-吸附Cl-前后的元素组成变化,测定了吸附等温线和吸附动力学曲线。结果表明,该吸附反应为介孔单分子层与多分子层吸附相结合,在70 h内达到吸附平衡,吸附量随Cl-初始浓度、温度的增加而增大,吸附过程遵循Lagergren二级反应动力学过程,相关系数R2为0.9981。

聚二甲基二烯丙基氯化铵对碳钢表面缓蚀性能的研究

采用失重法、电化学测量,探讨在不同工艺条件(腐蚀介质、添加浓度、温度、复配比)下,研究了聚二甲基二烯丙基氯化铵(PDMDAAC)环保型缓蚀剂对碳钢Q235的缓蚀性能,得出最佳工艺条件:10℃时,1 mol/L HCl腐蚀介质中,PDMDAAC浓度为0.5 g/L,PDMDAAC与KI质量复配比为1∶2,缓蚀效果最好,最高为95.78%。研究机理表明,其吸附过程符合Langmuir吸附等温线,吸附过程为以化学吸附为主的混合吸附,SEM、XPS结果验证了PDMDAAC可以在碳钢表面形成保护膜,抑制碳钢表面腐蚀。