基于量子力学和Mott-Schottky研究Alloy 690氧化膜的半导体特性

采用量子力学研究了Alloy 690中可能含有的氧化膜的半导体性质,并用Mott-Schottky曲线研究了在含有氯离子的介质中氧化膜半导体特性的变化规律。结果表明:Alloy 690中的主要氧化物Cr2O3、Ni O均为间隙半导体,带隙宽度分别为1.345 75、1.479 87e V;在溶液中加入侵蚀性离子Cl-后,合金表面形成具有双极性的n-p型膜,电容明显增大;钝化膜中含有很多金属离子空缺和氧空缺,表明施主或受主浓度增大。这些缺陷会使膜的动态平衡受到破坏,导致钝化膜易发生穿透性破裂而诱发局部腐蚀。     

通过电位阶跃法研究在Alloy600腐蚀体系中腐蚀剂的扩散过程

利用电化学工作站,通过改进使用电位阶跃法(计时电流法),以常用合金材料Alloy600、Alloy690和X80钢为研究对象,通过实验和理论分析来研究它们在不同溶液、不同温度条件下的腐蚀情况。研究结果表明,X80钢产生的极化电流较Alloy690、Alloy600要大很多;常温下Alloy690、Alloy600产生的氧化膜主要成分为Ni O,而X80钢产生的氧化膜主要成分为Fe2O3。     

电化学测试技术在缓蚀剂缓蚀行为研究中的应用

对常规的电化学测试方法在缓蚀剂性能评价及作用机理研究方面的应用现状进行了综述,介绍了新兴电化学测试技术在缓蚀剂研究领域的应用进展。进一步指出发展适合缓蚀体系特点的测试技术和研究方法将成为缓蚀剂性能研究的重要内容之一。结合现代表面分析技术,电化学测试技术在未来缓蚀剂领域中具有广阔的发展应用前景。     

高浓度氯离子环境中铜合金缓蚀的电化学研究

应用线性电位扫描(LSV)和Tafel实验等电化学测试技术,研究了苯并三氮唑(BTA)浓度、缓蚀剂的复配、温度对铜合金在高浓度氯离子(25%氯化钙溶液)环境中腐蚀行为的影响。结果表明:缓蚀剂浓度改变将引起缓蚀效果的变化,BTA浓度较低时,铜合金腐蚀电位随缓蚀剂浓度增大而升高,腐蚀速率降低;BTA浓度超过0.2%后,铜合金腐蚀电位和腐蚀速率趋于稳定;NaNO2、Na2MoO4、(NH4)2MoO4等缓蚀剂与BTA复配,对改善缓蚀效果有一定作用;温度对缓蚀效果有重要影响,铜合金在高浓度氯离子溶液中的腐蚀速率随温度的升高而加快,缓蚀剂的缓蚀效果随温度的升高而降低。     

塔里木油田常用钻井液垢下腐蚀性及缓蚀措施研究

主要研究了4种塔里木油田常用水基钻井液体系对钻具的垢下腐蚀情况,分析了腐蚀速率随时间变化的趋势。采用除氧剂HO-1和缓蚀剂IMC-03协同作用的措施,可对塔里木常用钻井液体系的垢下腐蚀产生良好的缓蚀效果。     

缓蚀剂WS对20A的缓蚀行为研究

用失重法、极化曲线法研究了缓蚀剂 WS 在5％盐酸溶液中对20A 的缓蚀行为,结果表明,缓蚀剂 WS 是混合型缓蚀剂,缓蚀效果良好。通过对 WS 加入浓度与缓蚀效率的研究,找到了 WS 在20A 上的吸附等温式。     

葡萄糖酸钠及其复配物对异种焊接的缓蚀性能研究

通过浸泡试验和电化学测试研究了环保型缓蚀剂葡萄糖酸钠、四硼酸钠以及它们的复配物对碳钢不锈钢焊接试样的缓蚀性能。结果表明,单组分的葡萄糖酸钠和四硼酸钠对碳钢不锈钢焊接试样具有一定的缓蚀作用。复配缓蚀剂最佳配比为90mg/L葡萄糖酸钠和360mg/L四硼酸钠,缓蚀效率达到最高为86.04%。     

XM——101自来水介质缓蚀剂对钢铁的缓蚀作用

ＸＭ－１０１自来水质缓蚀剂是由聚磷酸盐、醇胺磷酸酯和磷酸二氢锌组成的。它以抑制钢铁腐蚀为主,兼具一定的阻垢功能。当缓蚀剂浓度为７５×１０＾－６时,缓蚀率高达１００％。这种缓蚀剂不仅高效,而且剂量小、成本低,原材料无毒。     

HEDP对脱碳系统中结构钢的缓蚀作用

通过含有ＨＥＤＰ（１－羟基乙驻二磷酸）的碳酸不溶液中进行的腐蚀实验和物理化学测量，研究了ＨＥＤＰ对脱碳系统不锈钢和软钢缓蚀作用。通过腐蚀失重实验测得ＳＳ４１在大气了压操作条件下，在含有２００ｐｐｍＨＥＤＰ在溶液中的缓蚀率最大可达到８０％，接近Ｎａ２ＣｒＯ４和Ｖ２Ｏ５的缓蚀率，腐蚀失重实验测得的缓率结果与电化学测量结果一致。通过隧道扫描显微技术（ＳＴＭ）观察，ＨＥＤＰ分子是吸附在ＳＳ４１表面而引起民     

铝合金表面的缓蚀作用研究

首先借助扫描电镜观察了铝合金表面经不同pH水溶液腐蚀后的微观变化。SEM结果表明,在酸、碱条件下因腐蚀机理的不同,铝合金表面的微观变化也有明显差异。同时研究了常用的5种表面活性剂和2种工业缓蚀剂的缓蚀作用。实验结果表明,在pH=2的酸性条件下,表面活性剂中C12～14烷基糖苷(APG)、椰油脂肪酸二乙醇酰胺(6501)和烷基苯磺酸钠(LAS)的缓蚀效果较好;pH=9的碱性条件下,APG和6501的缓蚀效果较好;综合分析APG的缓蚀作用最佳;而对于2种工业缓蚀剂,在酸、碱条件下均有一个最佳缓蚀浓度。     

Localized corrosion behavior of scratches on nickel-base Alloy 690TT

Localized corrosion of scratched Alloy 690TT was studied using scanning electrochemical microscopy (SECM) in 10 wt.% NaOH solution and atomic force microscopy (AFM) after short-time oxidation tests in high temperature high pressure water at 250 °C. The results show that the scratches detected by SECM displayed more extensive electrochemical activity. The scratch groove and the whole deformed region caused by scratching as anode corresponded to the peak of tip current. The oxides formed in 250 °C high purity pressurized water nucleated preferentially at the scratch groove and grew faster than non-scratched surface. The nano-grained scratch groove has more electrochemical reactivity than mechanical twins at scratch banks. The intense localized corrosion could contribute to crack initiation at the bottom of scratch groove.     

硫酸盐对600镍基合金腐蚀行为影响的研究

本文采用塔菲尔极化曲线法和交流阻抗法,在常温条件下,研究了600镍基合金在硫酸盐溶液中的腐蚀电化学行为,并初步分析了其腐蚀电化学行为的机理。以及在300℃条件下,600镍基合金在硫酸盐溶液中的腐蚀行为。试验结果表明,硫酸根对600镍基合金有很强的腐蚀加快作为,浓度越大腐蚀加速的效应越明显,同时在高温条件下,600镍基合金出现了点蚀的腐蚀形态。     

Corrosion inhibition of mild steel by Calotropis procera leaves extract in a CO2 saturated sodium chloride solution

The Calotropis procera leaves extract (CPLE) was investigated as a corrosion inhibitor for mild steel in a CO₂-saturated 3.5 wt% NaCl solution using various electrochemical techniques. The results show that the CPLE is an effective inhibitor with inhibition efficiency of 80% using 50 ppm. Polarization studies show that the CPLE acts as a mixed inhibitor, and the adsorption of CPLE follows Langmuir adsorption isotherm. Molecular dynamics simulations reveal that the presence of N, O in the CPLE as well as π-electron systems coupled with high adsorption energies of interaction of the CPLE with steel are responsible for corrosion inhibition performance.     

Protection of copper surface in acidic chloride solution by non-toxic thiadiazole derivative

This paper deals with electrochemical properties of copper in the presence of the non-toxic compound 2-amino- 5-ethyl- 1,3,4-thiadiazole (AETDA) in acidic chloride solution. Electrochemical techniques: open circuit potential measurements, linear potentiodynamic measurements, cyclic voltammetry measurements and chronoamperometric measurements in addition to SEM–EDS analysis were used during the work. Results show that inhibition efficiency of 2-amino-5-ethyl-1,3,4-thiadiazole depends on inhibitor concentration and immersion time of copper electrode in inhibitor solution. Cyclic voltammetry and linear potentiodynamic measurements beside chronoamperometric measurements indicate formation of protective layer on copper surface. Moreover, results obtained by electrochemical measurements point out that the stability of formed layer depends primarily on the concentration of inhibitor and of potential values at which protective film is formed. Also, potentiodynamic measurements show that AETDA in acidic chloride solutions acts as mixed-type inhibitor. Inhibition mechanism of 2-amino-5-ethyl-1,3,4-thiadiazole includes adsorption of inhibitor on active sites on electrode surface which was confirmed by SEM–EDS analysis of the electrode surface. Adsorption of the AETDA in HCl solution obeys Langmuir adsorption isotherm.     

Starch-AA-CS三元共聚物对酸溶液中碳钢的缓蚀作用

以淀粉（Starch）、丙烯酸（AA）和壳聚糖（CS）为原料合成三元共聚物（SAAC）。利用红外光谱（FT-IR）和X射线衍射（XRD）进行结构表征,并通过电化学方法、失量法、扫描电子显微镜（SEM）和能谱仪（EDS）研究SAAC在1 mol·L^-1 HCl环境下对Q235碳钢的缓蚀作用及机理。结果显示,SAAC是一种混合型缓蚀剂,30℃时,200 mg·L^-1的SAAC的缓蚀率可达90.1%。通过Gibbs自由能和Tafel曲线可知,SAAC在Q235碳钢表面的吸附符合Langmuir吸附等温式,同时存在物理吸附与化学吸附。SAAC合成原料经济、环保,合成条件温和,是一种具有广泛应用前景的绿色环保型缓蚀剂。     

Effect of heterocyclic organic inhibitors on corrosion behavior of aluminum in 3.5% sodium chloride solution

添加有机缓蚀剂可以减缓或防止铝合金在3.5%NaCl溶液中的腐蚀。用失重法和电化学法分别研究了7种有机化合物对7075铝合金在3.5%NaCl溶液中的缓蚀行为,并用扫描电子显微镜(SEM)对铝合金样品在不同缓蚀介质中的腐蚀形貌进行了观测。失重法实验结果和Tafel极化测试结果均表明,这些有机化合物对铝合金有不同程度的缓蚀作用,其中7-氮杂吲哚的缓蚀效果最好,通过对铝合金样品表面孔蚀特征及电化学测量结果的分析,确定其缓蚀机理为阳极过程控制为主的成膜缓蚀剂。     

Corrosion inhibition of steel in sodium chloride solution by undoped polyaniline epoxy blend coating

In this study an undoped polyaniline (PAni) was synthesized by chemical oxidative polymerization with ammonium persulfate as an oxidizing reagent. The synthesized PAni was used as a corrosion inhibitive pigment in an epoxy matrix. The corrosion protection performance of steel coated panels in 3.5% sodium chloride solution was evaluated via determination of open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS). It was found that after 300 days of immersing the resistance of coating was about 4 × 10⁵ Ω cm². The OCP was shifted to the noble region due to the passivation effect of PAni pigment. Besides, the phase angle (theta) at 10 kHz was stable around 87 ± 1° during immersion period. Results revealed that PAni pigmented paint showed acceptable protection against the corrosion of carbon steel in 3.5% sodium chloride solution.     

土酸溶液中苯扎氯铵对不锈钢的缓蚀作用及吸附热力学研究

为了研究土酸介质中烷基季铵盐类阳离子表面活性剂对不锈钢的缓蚀及吸附作用,采用静态失重法在不同温度的10%土酸溶液中苯扎氯铵对304#不锈钢的缓蚀作用,应用吸附理论和Sek ine方法对静态挂片试验数据进行处理。结果表明,苯扎氯铵在不锈钢表面的定向吸附是产生缓蚀的主要原因,当其含量达到一定浓度后,缓蚀作用基本保持不变;在浓度为0~0.2%时,其在不锈钢表面的吸附服从Langmu ir吸附等温式,相关系数大于0.99;缓蚀率随浓度的增加和温度的升高而增大,是由吸附过程中表现为总熵增加的特点决定的;获得了吸附过程ΔHo、ΔSo和ΔGo等重要热力学参数。     

Electrochemical and morphological assessments of inhibition level of 8-hydroxylquinoline for AA2024-T4 alloy in 3.5% NaCl solution

The corrosion inhibition of AA2024-T4 in 3.5% NaCl solution by 8-hydroxylquinoline (8-HQ) was investigated by potentiodynamic polarisation (PDP), electrochemical impedance spectroscopy and dynamic electrochemical impedance spectroscopy. Experimental results were supported with scanning electron microscopy (SEM), atomic force microscopy and Fourier transform-infrared (FTIR) spectroscopy analysis. It was found that 8-HQ molecules adsorbed on the alloy surface and protected it against corrosion. SEM, energy dispersive spectroscopy, and FTIR results confirm the adsorption of 8-HQ molecules on AA2024-T4. The inhibition efficiency of 8-HQ is found to increase with increase in concentration and the highest concentration studied (0.05 M) offered corrosion inhibition efficiency of 84%. PDP results show that 8-HQ acts as mixed type inhibitor in the studied medium.     

Electrochemical noise analysis of LY12-T3 in EXCO solution by discrete wavelet transform technique

Electrochemical noise technique coupled with SEM was used to study the corrosion process of LY12-T3 in the modulated EXCO test solution, and the EN data were analyzed by wavelet technique based on orthogonal db4 wavelet. The results show that, under the experimental conditions, the characteristics of energy distribution plot (EDP) obtained from wavelet analysis technique can be used as “fingerprints” of EN signal and can be used to differentiate the corrosion type. With the change of corrosion type of LY12-T3 from pitting corrosion through intergranular corrosion to exfoliation corrosion, the maximum relative energy defined in EDP will change from the region of crystal series coefficients with smaller scales through middle scales to larger scales.