55%溴化锂溶液中Na2MoO4-B复合缓蚀剂对碳钢的缓蚀行为研究

本文采用失重法、电化学测试技术、EDAX能谱和X－射线衍射等方法考察了Na₂MoO₄-B复合缓蚀剂对55%LiBr+0.07 mol/L LiOH溶液中碳钢的缓蚀行为.结果表明,240 ℃时添加800 mg/L Na₂MoO₄-B复合缓蚀剂的55%LiBr+0.07 mol/L LiOH溶液中碳钢腐蚀速度为44.11 μm/a.沸腾的55%LiBr+0.07 mol/L LiOH溶液中添加复合缓蚀剂后碳钢电化学性能明显改善,腐蚀电位正移,钝化电位区间拓宽,钝化电流密度降低,常相位角元件CPE的Y₀值减小,反应电阻Rt值增加,缓蚀效率可达98.88%.Na₂MoO₄-B复合缓蚀剂中的B缓蚀剂可使55%LiBr溶液中Na₂MoO₄的溶解度提高至800 mg/L以上.Na₂MoO₄通过氧化作用可使碳钢表面形成一层主要由Fe₃O₄、MoO₂和MoO₃组成的致密钝化膜,从而起到较好的缓蚀作用.     

高温高浓度溴化锂溶液中碳钢钝化膜形成机理研究

采用电化学测试技术、化学浸泡方法和现代物理测试技术,探讨了高温高浓度溴化锂溶液中碳钢钝化膜的结构及形成机理。结果表明,在55％LiBr 0.07mol/L LiOH溶液中（145℃）,随Na2MoO4浓度增加碳钢极化阻抗升高,析氢量减少,当其浓度达到150mg/L以上时对碳钢具有良好的缓蚀效果;MoO4^2-在金属表面还原而参与钝化膜生成,在膜的生长过程中吸附于膜的薄弱点形成MoO3,膜中Mo的不同价态形成的电场抑制了碳钢的活性溶解;MoO4^2-还原反应遵循下列反应方程：MoO4^2- 2H2O 2－→MoO2 4OH^-。     

葡萄糖与甘氨酸反应产物对碳钢的缓蚀效果

为了解葡萄糖与甘氨酸反应产物对碳钢的缓蚀效果,采用失重法、电化学法并结合扫描电镜观察,研究了葡萄糖与甘氨酸反应产物(PGG)对碳钢在1 mol/L HCl溶液中的腐蚀抑制作用。结果发现:PGG对碳钢表现出很好的缓蚀效果,缓蚀效率随添加浓度的增加而增加,在最大浓度250 mg/L时,表现出最好的缓蚀效果,缓蚀效率为94.7%,且缓蚀效率随温度升高而降低。PGG同时抑制了碳钢腐蚀的阴极还原反应和阳极氧化反应过程,为混合型缓蚀剂,是通过多组分的物理和化学联合吸附,在碳钢表面上形成保护性覆盖层,将碳钢与酸溶液隔离,从而起到缓蚀作用,其吸附行为遵循Langmuir吸附等温模型。葡萄糖与甘氨酸反应产物(PGG)是碳钢在1 mol/L HCl溶液中的优良缓蚀剂。     

钼酸锂对碳钢在溴化锂溶液中腐蚀的影响

本文通过静态挂片法研究了钼酸锂对碳钢在溴化锂溶液中缓蚀的作用，并通过极化曲线探讨其缓蚀作用的机理，用扫描电镜观察形成的表面膜形态，用X-射线衍射法对形成的表面膜层结构进行分析。实验表明钼酸锂对碳钢在溴化锂溶液中有一定的缓蚀作用，其中添加0．020mol／L钼酸锂和0．20mol／L氢氧化锂显著抑制溴化锂溶液对碳钢的腐蚀，其可能是在碳钢表面形成一层三氧化二铁、钼酸锂和三氧化钼组成的钝化镆，阻滞阳极反应从而起到缓蚀作用。     

盐酸介质中咪唑啉缓蚀剂的性能

开发咪唑啉型缓蚀剂及其衍生物,探讨其腐蚀机理对于金属的腐蚀防护意义重大.为此,用月桂酸和二乙烯三胺合成了咪唑啉型缓蚀剂,通过静态失重法、线性扫描极化曲线法考察了其在5%HCl溶液中的缓蚀电化学性能及与KI的协同作用.结果表明:该缓蚀剂对A3碳钢的腐蚀具有明显的抑制作用,浓度为30 mg/L时缓蚀率达到99.0%;可以有效抑制腐蚀过程中的阳极反应;与Ⅺ有良好的缓蚀协同作用,10mg/L缓蚀剂与10 mg/L KI复配可以使缓蚀率达到99.2%,并且能将腐蚀速率控制在0.6 g/(m2·h)以下.     

BTA对碳钢在溴化锂溶液中腐蚀的影响

本文通过静态挂片法研究了ＢＴＡ 对碳钢在溴化锂溶液中缓蚀的作用, 并通过极化曲线法探讨其缓蚀作用的机理。实验表明ＢＴＡ对碳钢在溴化锂溶液中有一定的缓蚀作用, 其中添加Ｏ．２０ ｍ ｏｌ／ｄｍ ３ ＢＴＡ 和Ｏ．１５ ｍ ｏｌ／ｄｍ ３ 的氢氧化锂可显著降低溴化锂溶液对碳钢的腐蚀, 其可能是在碳钢表面形成一层ＢＴＡ－ Ｆｅ （Ⅱ） 吸附膜, 阻滞阳极反应从而起到缓蚀作用。     

一种含硫杂环双席夫碱化合物在硫酸介质中对Q235碳钢的缓蚀作用

目前对于双席夫碱化合物用作碳钢缓蚀剂的研究报道较少。合成了一种含硫杂环双席夫碱化合物:双噻吩-2-甲醛缩邻苯二胺(DTCPA),采用静态失重法、动电位极化曲线和交流阻抗谱测试考察了其在0.5 mol/L H_2SO_4溶液中对Q235碳钢的缓蚀作用。结果表明,DTCPA对碳钢具有良好的缓蚀效果,随着DTCPA浓度的增加腐蚀速率下降,缓蚀效率不断提高;然而,随着温度升高,腐蚀速率加快,缓蚀效率下降。DTCPA在硫酸介质中对碳钢的缓蚀作用属于一种抑制阴阳两极反应的混合型缓蚀剂,在碳钢表面形成了一层致密的保护膜,有效阻挡了硫酸对碳钢的腐蚀,其在碳钢表面的吸附遵循Langmuir吸附等温式。     

Na_2MoO_4与苯并三氮唑在ClO_2介质中对黄铜的协同缓蚀作用

为了寻求ClO2体系中高效、环保的铜缓蚀剂,采用静态失重法、动电位极化曲线和扫描电镜研究了Na2MoO4与苯并三氮唑(BTA)单独及复配使用时在ClO2介质中对黄铜的协同缓蚀效应。结果表明:Na2MoO4对黄铜的缓蚀作用有限,最大缓蚀率仅为10.85%;BTA对黄铜有较好的缓蚀作用,缓蚀效率随其浓度的增加而增大,到达一定值后缓蚀率不再随BTA浓度的增加而明显变化;Na2MoO4与BTA按质量浓度1∶1复配后对黄铜产生明显的协同缓蚀作用,最大缓蚀率可达81.01%。     

海水中钨酸盐复合缓蚀剂对碳钢的缓蚀性能

将海水用于工业可大量节省淡水资源,但海水会对金属设备产生严重腐蚀.采用失重法、极化曲线和表面分析技术就海水中钨酸盐复合缓蚀剂对碳钢(A3)的缓蚀性能及缓蚀机理进行了研究,确定了与钨酸盐具有较好协同效应的缓蚀剂配方.结果表明:单一的钨酸盐对海水中碳钢的缓蚀率随其浓度的增加而增加,浓度低缓蚀率低,40 mg/L以下会加速碳钢腐蚀;四元复合缓蚀剂中钨酸盐、柠檬酸、HEDP和锌盐浓度分别为30,40,10,3 mg/L时,对A3钢的缓蚀率超过93%;单一钨酸盐及其复合缓蚀剂均为阳极型缓蚀剂;添加缓蚀剂后A3钢表面以氧化铁为主要成分,钨与磷也参与了不溶性沉淀膜的形成,有效地抑制了海水对碳钢的腐蚀.     

硫脲和I~-对碳钢在酸洗液中的协同缓蚀作用

目前,鲜见硫脲与I~-的复配技术及其在酸洗液中对碳钢缓蚀性能的报道。采用失重法、开路电位、电化学交流阻抗谱和动电位极化曲线,研究了硫脲和I~-在硫酸洗液中对碳钢的协同缓蚀效应,并采用扫描电镜对碳钢腐蚀前后的腐蚀形貌进行表征。结果发现,硫脲和I~-复配后可明显降低碳钢在硫酸洗液中的腐蚀速率,在含0.01mol/L硫脲的硫酸溶液中,添加0.01 mol/L的I~-可将对碳钢的缓蚀效率从88.7%提高到96.1%。     

聚天冬氨酸对铜、碳钢缓蚀性能的影响

采用失重法研究了pH=7.5的自来水中聚天冬氨酸和苯骈三唑、钼酸钠、硅酸钠复配时对铜和碳钢-铜复合体系的缓蚀效果,试验表明:单一聚天冬氨酸和钼酸钠的缓蚀效果随其浓度的增加而增加;单一苯骈三唑的缓蚀效果随其浓度的增加其缓蚀性也增加,当浓度达3 mg/L时,缓蚀效果最佳;单一硅酸钠的缓蚀效果随其浓度的增加其缓蚀性也增加,当浓度达200 mg/L时,缓蚀效果最佳;在缓蚀剂总浓度为50.5 mg/L时4种药剂复配,显示出较好的协同效应,其最佳配比为10 mg/L聚天冬氨酸 0.5 mg/L苯骈三唑 10 mg/L钼酸钠 30 mg/L硅酸钠.电化学动电位极化曲线测试结果表明复合水处理剂对阳极、阴极均有缓蚀作用.     

水溶性环烷基咪唑啉甜菜碱的合成及其对碳钢的缓蚀性能

目前,对水溶性环烷基咪唑啉甜菜碱的合成和应用研究不够,用环烷酸、三乙烯四胺、氯乙酸钠等原料合成后作碳钢缓蚀剂,用静态挂片失重法和电化学方法,研究了其在HCl,HCl-H2S水相体系中的缓蚀性能。结果表明：水溶性环烷基咪唑啉甜菜碱在1000mg／LHCl腐蚀体系中为以抑制阳极过程为主的阴阳极混合型缓蚀剂,在HCl,HCl...     

A green and effective corrosion inhibitor of functionalized carbon dots

In this work, a green and effective corrosion inhibitor of functionalized carbon dots (FCDs) was synthesized by the conjugation of imidazole and citric acid carbon dots (CA-CDs). The corrosion inhibition behavior of FCDs for Q235 steel in 1 M HCl solution was systematically investigated by electrochemical analysis, corrosion morphology and adsorption isotherm. The electrochemical results implied that the as-prepared FCDs inhibitor could effectively suppress the corrosion of Q235 steel in 1 M HCl solution. At the same time, the inhibition efficiency of steel in 1 M HCl solution was more than 90% when the inhibitor concentration exceeded 100 mg/L. This excellent property was attributed to the coverage of adsorption film on the steel surface, which conformed to the Langmuir adsorption model. In addition, the analysis of adsorption isotherm displayed that the adsorption mechanism was the physicochemical interaction at the steel/solution interface.     

One pot graphene-based nanocontainers as effective anticorrosion agents in epoxy-based coatings

A novel nanocontainer using graphene oxide nanoscrolls (GONS) as shell and benzotriazole (BTA) as core is proposed and embedded in epoxy coating for the corrosion protection of carbon steel. BTA/GONS nanocontainer is effectively fabricated by a modified shock-cooling approach. The hybrid material takes the specific shape of graphene oxide sheet spirally wrapped into scroll structure, acting as favorable physical barrier to afford encapsulation performance. A high uptake and storage of BTA in GONS is achieved, showing a loading capacity of 78.40%. The fantastically scrolled structure also provides an effective network to well control the BTA liberation during long-term immersion. The transport of BTA is diverse with pH values. The maximum release capacity of BTA occurs in neutral condition, larger than that in acid or alkaline environment. The liberation for up to 456 h exhibits the steady releasing characteristics of the containers. The corrosion inhibition performance of BTA/GNOS containers was mainly evaluated by electrochemical impedance spectroscopy. In comparison with, the reference epoxy coating, the one modified by BTA/GNOS nanocontainers demonstrate more excellent anticorrosion ability. The successful embedding and homogeneous distribution of BTA-loaded GNOS nanocontainers in epoxy film contributes to the improvement in the corrosion resistance of Q235 carbon steel and the self-healing performance of the coating.     

Effect of PWVA/Sb2O3 complex inhibitor on the corrosion behavior of carbon steel in 55%LiBr solution

The inhibition performance of PWVA/Sb₂O₃ complex inhibitor on carbon steel was studied in 55%LiBr + 0.07 mol L⁻¹ LiOH solution. Results indicated that the complex inhibitor decreased both anodic and cathodic polarization current density and widened the passive potential region of carbon steel in test solution and can be classified as mixed inhibitor. The complex inhibitor exhibited excellent inhibition performance on carbon steel when the concentrations of PWVA and Sb₂O₃ were 300 and 200 mg L⁻¹, respectively. With the solution temperature increasing from 145 to 240 °C, the corrosion rates of carbon steel increased from 4.71 to 120.66 μm y⁻¹. In solution containing the complex inhibitor, the relationship between relative coverage ratio of inhibitor on carbon steel surface and inhibition efficiency at 145 °C was obtained as the equation μ = 0.94η, it was a direct proportion. This result proved that the complex inhibitor inhibited the corrosion of carbon steel by geometric blocking effect. When solution temperature was 160 °C, the adsorption Gibbs free energy of PWVA and Sb₂O₃ on carbon steel were −49.59 and −44.29 kJ mol⁻¹, respectively. It indicated that the adsorption processes of PWVA and Sb₂O₃ on carbon steel surface were spontaneous processes. As a strong oxidant, PWVA facilitated the compact passive film comprising of FeO, Fe₂O₃ and Fe₃O₄ forming on the surface and itself was reduced to heteropoly blue. Sb₂O₃ adsorbed on carbon steel surface formed an adsorption film. PWVA and Sb₂O₃ behaved synergistic effect. The corrosion resistance performance of carbon steel in 55%LiBr + 0.07 mol L⁻¹ LiOH solution was improved by PWVA/Sb₂O₃ complex inhibitor.     

HCO_3~-对J55钢腐蚀行为的影响

油田地下水中HCO_3~-含量较高,对油田套管钢J55的电化学行为有较大影响.为此,利用动电位极化曲线和扫描电镜(SEM)研究了J55钢在不同浓度NaHCO_3溶液中的腐蚀行为.结果表明,在试验条件下,HCO_3~-的浓度低于5 g/L(即0.06 mol/,L)对J55钢的腐蚀起促进作用,高于5 g/L起抑制作用;随着HCO_3~-浓度的增加,J55钢的二次钝化速度增大,钝化区间范围增大,维钝电流密度减小;J55钢的击穿电位降低,基本维持在1.00～1.15V之间;随着HCO_3~-浓度的增大,阴极反应速率增大,O_2+4HCO_3~-+4e→4CO_3~(2-)+2H_2O是主要的阴极反应,而O_2+2H_2O+4e→4OH~-反应是在-0.9 V以后才开始发生的.     

Cl~-和H_2S对不锈钢电化学行为的协同影响

目前,对Cl~-和H_2S共存条件下不锈钢的腐蚀尤其是点蚀行为鲜有研究。采用动电位扫描和交流阻抗测试研究了304,316L和2205 3种不锈钢在含有不同浓度Cl~-和H_2S的溶液中的电化学行为。结果表明:在含有1 200 mg/L Cl~-的溶液中,随H_2S浓度增大,304和316L的点蚀敏感性均增大,但此条件下的H_2S浓度并未对2205双相不锈钢产生影响。当Cl~-浓度增大到1 500 mg/L时,2205产生了点蚀现象,说明虽然H_2S促进了不锈钢点蚀的发生,但Cl~-是诱导不锈钢产生点蚀的关键因素。     

Experimental Study on the Effect of the Water-Cut Conditions on the Performance of L80 Carbon Steel

In the oil production, water and acidic gases, i.e., H₂S and CO₂, are co-produced with the oil. The acidic gases are known to associate with a variety of corrosion damage to the surface facilities leading to costly failures. Also, the acidic gases cause a reduction in the service life of equipment. Corrosion of API L80 tubular carbon steel in sweet media (in the presence of CO₂ gas) was investigated using the linear polarization resistance meter. Experiments using API L80 tubular carbon steel material were carried out in a stagnant flow condition with different ratios of produced water to crude oil at relatively high temperatures (60 °C up to 90 °C). The pressure was about 200 psi (13.8 bar) of CO_2, and the experiments were carried out using a high pressure vessel namely an autoclave cell. Under those experimental conditions, results indicated that at a temperature of 60 °C, the corrosion rate for carbon steel L80 increased as water-cut ratio increased. Also, the results showed that at higher temperature than 60 °C, the formation of iron carbonate scale on the surface of the steel was observed to increase. Consequently, the corrosion rate of the L80 carbon steel was observed to decrease.     

Ca~(2+)和臭氧对A3碳钢表面磷化膜的影响

在低温磷化条件下, 在磷化液中加入Ca ²⁺并以臭氧作为促进剂, 在A3碳钢表面制备了磷化膜。通过SEM、
XRD、EDS、FT--IR以及腐蚀电化学测试等手段对磷化膜进行表征, 研究了Ca ²⁺和臭氧对磷化膜的结构和性能的影响。结果表明, 在磷化液中添加Ca ²⁺所得磷化膜的质量随着Ca ²⁺浓度的提高而减小, 添加Ca ²⁺可细化磷化膜的晶粒、提高磷化膜的致密度和耐蚀性能; 溶解在磷化液中的臭氧具有细化磷化膜晶粒和促进晶粒生长的作用, 能大幅提高磷化膜晶粒的形核率和磷化膜的主体形成速度。当磷化液的pH=2.70、Ca ²⁺浓度为1.8 g/L、臭氧含量为2.50 mg/L时, 磷化膜的质量为5.46 g/m², 其耐硫酸铜点滴腐蚀时间超过122 s, 在5% NaCl溶液中的腐蚀电流为0.50 μA/cm²。