HSn70-1B铜管在中性NaCl溶液中的腐蚀行为

利用原子吸收光谱、电子衍射、电子显微镜等测试技 术，对在不同含量的NaCl中性水溶液中HSn70-1B铜管的腐蚀行为进行研究.在中性NaC l溶液中HSn70-1B铜管的腐蚀行为主要受表面膜的形成过程和组成所控制，可分为2个 阶段：氯离子含量在0 mol/L～0.02 mol/L时，合金表面逐渐形成较完整的Cu2O表面膜， 保护性增 强；氯离子含量在0.02 mol/L～0.05 mol/L时，Cu2O膜减薄而变得不完整，合金逐渐进入 均匀腐蚀状态.     

不同温度下X80钢的CO2腐蚀电化学特性

采用动电位扫描和交流阻抗技术研究了常压条件下X80钢CO2腐蚀电化学特性。结果表明:在30～80℃范围内,阳极反应机理没有发生变化,而阴极反应机理在60℃时已经发生改变;在阳极极化条件下,X80钢CO2腐蚀的电化学阻抗谱(EIS)曲线具有三个时间常数,其中低频感抗弧与试样表面活化溶解有关,低频容抗弧与试样表面腐蚀产物膜生成有关;随着温度的升高,EIS曲线低频区感抗弧逐渐缩小,容抗弧逐渐扩大。     

N80钢CO2腐蚀电极过程交流阻抗分析

利用交流阻抗技术研究了N80钢在不同介质条件下CO2腐蚀交流阻抗图谱的特征，结果表明，N80油套管钢CO2腐蚀EIS曲线具有三个时间常数，其中低频感抗弧与试样表面活化溶解有关，低频容抗弧与试样表面腐蚀产物膜生成有关。随着试样表面腐蚀产物膜覆盖度增大，EIS曲线低频区感抗弧逐渐缩小，容抗弧逐渐扩大。进一步讨论了试样表面腐蚀产物膜成膜情况与电极反应过程的有关。     

海水管路黄铜焊接接头在人工海水中的电化学阻抗谱

利用扫描电镜(SEM)、阳极极化与电化学阻抗谱(EIS)试验方法,研究了紫铜管路中的黄铜焊缝在人工海水中的腐蚀特性。结果表明,在Tafel区,黄铜焊缝以CuCl2-络合离子和Zn2 溶解,并且CuCl2-和Zn2 的扩散是该溶解过程的控制步骤;当电极电位极化到-0.01～ 0.31V时,难溶物Cu2O、CuCl、ZnO和Zn(OH)2ZnCl2附着在电极表面阻碍电极极化,因而在EIS谱图上出现2个容抗弧;电极电位超过 0.31V后,难溶物开始溶解至 0.57V完全溶解,这时电极反应以脱锌腐蚀为主,电极过程为Zn2 离子向溶液扩散控制。     

多弧离子镀Al涂层对310不锈钢在熔融碳酸盐中的腐蚀的影响

采用多弧离子镀技术在310不锈钢表面制备Al涂层并经高温扩散退火,在合金表面形成铝化物涂层.采用电化学阻抗谱技术研究其在650℃熔融碳酸盐中的腐蚀行为.结果表明,310不锈钢的腐蚀电化学阻抗谱由双容抗弧组成,随着时间的延长,在低频端出现传质控制的特征.而涂层的腐蚀电化学阻抗谱仍由双容抗弧组成,但阻抗值明显增加.铝涂层的优异抗腐蚀性能是由于在表面形成了连续的保护性LiAlO_2(Al_2O_3)膜.     

硫酸盐还原菌对A3钢电化学腐蚀行为的影响

采用交流阻抗技术和动电位扫描法测Tafel曲线技术 对A3钢在含不同浓度硫酸盐还原菌介质中且未除氧条件下的电化学特性进行了研究，并采用SEM观察试样表面的腐蚀状况.结果表明：硫酸盐还原茵可以促进A3钢的阴极去极化和阳极极化，Ecorr降低；不同菌液浓度中的A3钢的交流阻抗谱图均呈单容抗弧特征，极化电阻Rp随菌液浓度增大而增大. SRB对腐蚀的影响作用与生成的生物膜的致密程 度有关.     

水中硫化物对Cu合金、碳钢的加速腐蚀作用及硫化物的去除研究

用失重法、表面分析法研究了水中硫化物对HSn70-1+As、B30、20#钢的腐蚀行为，认为水中硫化物对HSn70-1+As、B30、20#钢有加速腐蚀作用，HSn70-1+As发生的是脱Zn腐蚀，20#钢发生的是均匀腐蚀；通过实验室小型除S2-试验，探讨了工业硫酸亚铁和工业聚合硫酸铁的除S2-原理和除S2-效果，得到了实验室用工业硫酸亚铁和工业聚合硫酸铁除S2-的最佳加药量.动态模拟除S2-试验结果表明，工业硫酸亚铁除S2-效果好、速度快.     

温度对N80钢在饱和CO2地层水中腐蚀电化学性能的影响

利用交流阻抗技术研究了温度对N80油套管钢在模拟地层水中CO2腐蚀过程的影响.结果表明,低温下阻抗谱出现了高频容抗弧、中低频感抗弧和低频容抗弧3个时间常数,其中高频容抗弧与双电层电容和传递电阻有关,感抗弧对应膜的活性溶解,低频容抗弧与试样表面膜的生成有关.随着温度的升高,感抗弧逐渐缩小,直至消失,而低频的容抗弧则逐渐扩大,表明温度的升高有利于腐蚀膜的生成.随着浸泡时间的延长和温度的升高,腐蚀过程的传递电阻增加,这与高温下生成腐蚀膜的致密性有关.     

3.5%NaCl溶液中AISI304不锈钢的电化学行为及有机硅涂层的防护

应用电化学交流阻抗技术(EIS)研究了AISI304不锈钢 在35%NaCl溶液中的电化学行为及表面涂敷有机硅涂料后的电化学行为.结果表明，AISI304不锈钢在在开路电位下的交流阻抗表现为单容抗弧，在浸泡初期，随着时间的延长，耐蚀性提高，当浸泡120?d后，耐蚀性明显下降.不锈钢表面涂敷一层有机硅涂料后，EIS发生了较大变化，浸泡初期为单容抗弧，阻抗值明显增大，浸泡1天后表现为双容抗弧，而不锈钢裸样的始终表现为单容抗弧.     

腐蚀产物膜覆盖条件下油套管钢C02腐蚀电化学特征

采用动电位扫描和交流阻抗技术研究了腐蚀产物膜覆盖条件下2种油套管钢CO2腐蚀电化学特征．结果表明，油套管钢表面生成腐蚀产物膜以后可以显著降低腐蚀电流密度，EIS图谱中出现Warburg阻抗特征，含Cr油套管钢CO2腐蚀产物膜对基体的保护作用要优于N80钢．N80油套管钢在CO2腐蚀过程中的点蚀会使交流阻抗谱出现容抗弧特征．     

Effect of tin modification on corrosion of AM70 magnesium alloy

In this study, AM70 magnesium alloys with and without 2 wt.% Sn addition are compared for their corrosion performance. They are found to have similar corrosion rates in the first 70 h in 5 wt.% NaCl solution, but in extended immersion test the Sn modified AM70 exhibits accelerated overall corrosion. Nevertheless, Sn modification significantly decreases the susceptibility of the alloy to localized corrosion attack. Polarization curve measurements further indicate that the Sn modified AM70 is likely to have worse galvanic corrosion than AM70 in terms of the loss of metal, but again the Sn modification makes the galvanic corrosion less localized, which is an improvement aspect of the galvanic corrosion performance. The effect of Sn addition on the corrosion behavior appears to be associated with the presence of Sn-containing particles and the solute Sn in the matrix phase, which may change the electrochemical anodic and cathodic polarization behavior of the alloy.     

含H2S的硫酸溶液中Cl^—对铁阳极溶解的影响

应用电化学动电位扫描方法研究了在含低浓度Ｈ２Ｓ的硫酸溶液中Ｃｌ＾－对铁阳极溶解的影响。采用量子化学计算方法,得到了Ｃｌ＾－与ＨＳ＾－在电极表面吸附的稳定形态,优化计算了阳极电位下Ｃｌ＾－与ＨＳ＾－竞争吸附的总能量,结合能和Ｆｅ原子净电荷分布。     

Study of the corrosion behaviour of Cu-10Sn bronze in aerated Na2SO4 aqueous solution

Investigation of the electrochemical behaviour of Cu-10Sn (wt.%) alloy has been conducted in aerated aqueous sulphate solution and compared to that of pure Cu and Sn. Eoc versus time and cathodic and anodic polarizations have been performed as a function of the initial sulphate concentration, the rotation speed of the electrode and the immersion time. The surface layer have been characterized by scanning electron microscopy (SEM) and analyzed by energy dispersive spectrometry (EDS) and Fourier transform infrared spectroscopy (FTIR). The anodic behaviour evidences a Cu dissolution phenomenon on the corrosion layer limited by migration process rather than diffusion. The corrosion process conducts to preserve the original surface of the electrode and conducts to an internal growth at the layer/alloy interface, from the initial surface towards the unaltered substrate. The interphase behaviour is governed by the layer formed at Eoc under the experimental conditions and its evolution during the time. Hydroxyl-oxy and sulphate Cu and Sn compounds recover the surface and confer to the interface a blocking behaviour mainly due to the presence of the tin compounds in the layer. The global interphase behaviour matches the Type-I model of blocking adherent layer with decuprification phenomenon evidenced on archaeological bronzes.     

Electrochemical behaviour of lead alloys as anodes in zinc electrowinning

Abstract

The electrochemical and corrosion properties of the ternary and quaternary lead alloys Pb–0·18Ag–0·012Co, Pb–0·2Ag–0·06Sn–0·03Co, and Pb–0·2Ag–0·12Sn–0·06Co (wt-%) have been investigated. The formation of oxide layers on the surface of these alloys was traced by cyclic voltammetric methods and the composition of the anodic oxide layers was determined by X-ray and SEM analyses. The cobalt inclusions reduce the anodic polarisation and improve the corrosion resistance of the alloy. The Pb–0·2Ag–0·12Sn–0·06Co alloy displays electrochemical and corrosion properties similar to those of Pb–1Ag and can be used as a substitute for the latter as a material for anodes in the electrowinning of zinc from sulphate electrolytes.     

X70管线钢在HCO-3/CO2-3体系中表面膜性能研究

采用动电位扫描和交流阻抗方法研究了X70管线钢在0.5 mol/L Na2CO3+1 mol/L NaHCO3溶液中的阳极极化过程中的电化学行为,通过XPS和SEM对表面膜的组成和形貌进行了分析.结果表明，X70管线钢在阳极极化过程中分别于-600 mV和-350 mV电位处出现2个阳极电流峰；-600 mV时电极表面的反应阻力较小，表面膜主要由FeCO3、Fe2(OH)2CO3和FeOOH等化合物组成，表面膜上存在较多的微孔缺陷，处在一个不稳定状态，表面膜的保护性能较差；-350 mV时电极表面的反应电阻较大, 表面膜主要由铁的氧化物Fe2O3和Fe3O4组成,表面膜具有较好的保护性能.       

含RE铝阳极中析出相的电化学行为研究

用电子探针和能谱分析技术，观察了Al-5Zn-0．05In-0．1Sn-1Mg-0．3RE阳极中主要析出相的成分，并熔炼了析出相合金．电位测量和腐蚀后铝阳极表面的电子探针面扫描分析表明：富Sn相为阳极相，富Fe相、富RE相为阴极相；Fe相是铝阳极自腐蚀微电池中的主要阴极相，温度对析出相的电化学行为有影响．     

Corrosion behaviour of Cu-10Sn bronze in aerated NaCl aqueous media - Electrochemical investigation

Investigation of the electrochemical behaviour of Cu-10Sn (wt.%) alloy has been conducted in aerated aqueous chloride solutions and compared to that of pure Cu and Sn. Cathodic and anodic bronze behaviours have been investigated in function of the chloride concentrations (0.1-0.001 M), the rotation speed of the electrode and the potential sweep rate after 1-h immersion time in open-circuit conditions. At the corrosion potential, the corrosion behaviour appears determined by the charge-transfer controlled reduction of oxygen and the mixed charge- and mass-transfer controlled electrodissolution. In 0.1 M NaCl solution, three anodic regions are evidenced corresponding to: (I) a dissolution part from Eoc value, (II) a maximum current region corresponding to peaks formation and (III) a large current plateau. A partial protective effect of the corrosion product layer is observed at high anodic potential. It has been interpreted as the result of a 3D growth mechanism involving the formation of stable tin species in the layer according to a “pore resistance model”. Results on synthetic alloy are compared with those obtained on an archaeological bronze with a similar composition immersed in the same medium. Equivalent interface behaviour is evidenced between the synthetic and the archaeological bronzes.     

Corrosion electrochemical behavior of brass tubes in circulating cooling seawater

Electrochemical impedance spectroscopy(EIS) and electrochemical noise(EN) were used to study the corrosion electrochemical behavior of brass tubes in circulating cooling seawater using the developed sensor. EIS study shows that the inhibitor can lead to the formation of corrosion products on metal surface, which will then inhibit the corrosion process. When the flow rate of the seawater increases, the diffusion of oxygen speeds up and the action of filming on HA177-2 tube accelerates, resulting in decrease of corrosion rate. EN analysis shows that the flow rate of the seawater has little effect on pitting susceptivity of HSn70-1 tube; however the pitting susceptivity of HA177-2 tube increases with increasing flow rate. Good agreement is observed between the spectral noise resistance R30(f) calculated from EN data and the modulus of impedance. It is shown that the electrochemical noise technique can be used in corrosion monitoring.     

氨性溶液中砷黄铁矿阳极氧化过程的电化学

通过电化学研究 ,考察了氨溶液中砷黄铁矿的阳极氧化反应。实验表明氧化生成的表面膜对反应有抑制作用 ,该膜具有多孔性 ,可使反应继续进行。低温时 ,阳极氧化过程由电化学反应控制 ;高温时 ,反应受扩散过程控制。氨浓度对氧化过程的反应速率没有显著影响 ,溶液中Cu2 能降低氧化峰电位 ,改变氧化表面膜的形态 ,使膜的孔隙增大 ,反应速度加快。砷黄铁矿的阳极氧化总反应为FeAsS 11H2 O =Fe(OH) 3 SO2 -4 HAsO2 -4 18H 14e。