硫酸盐还原菌对铜合金腐蚀电化学行为的影响

用电化学方法研究了硫酸盐还原菌（SRB）生物膜对HSn70-lAB和BFe30-1-1铜合金腐蚀的电化学行为；用扫描电镜（SEM）和透射电镜（TEM）及X-射线能谱（EDS）分析了铜合金表面生物膜特征及其成分。结果表明，铜合金表面生物腐蚀与SRB的生长特性密切相关，SRB处于指数生长期时，Hsn70-lAB和BFe30-1-1铜合金的自腐蚀电位（Ecarr）和极化电阻（彤均迅速下降，腐蚀加剧，且后者腐蚀速度大于前者；而当SRB进人稳定生长阶段，两种合金的Ecarr和Rp均缓慢下降，腐蚀速度减缓，且二者腐蚀速度接近。表面生物膜的特征也有较大区别，HSn70-lAB铜合金表面的腐蚀产物膜比较平滑，BFe30-1-1铜合金表面的腐蚀产物膜较粗糙；且后者表面膜中S含量高于前者，腐蚀倾向明显增强。     

用原子力显微镜研究铜合金微生物的腐蚀行为

用原子力显微镜(AFM)研究了HSn70-1A、HSn70-1B和HSn70-1AB等3种铜合金在硫酸盐还原菌(SRB)菌液中的微生物腐蚀行为.结果表明,3种铜合金表面形成的生物膜形貌各不相同.HSn70-1AB合金表面生物膜的粗糙度大于其余两种合金,表明其生物膜最不均匀.去除生物膜后,3种样品的腐蚀形貌也小相同,粗糙度均有所增加,这是微生物腐蚀作用的结果.研究证实,AFM的定量分析能力是研究材料微生物腐蚀的重要手段.     

磁场对Q235钢微生物腐蚀行为的影响

采用腐蚀失重法、电化学测量技术和表面分析技术研究硫酸盐还原菌 (SRB) 在外加磁场下对Q235钢的腐蚀行为。结果表明,磁场条件下SRB对Q235钢的腐蚀作用较无磁场条件下减轻,其阻抗值先减小后增大,而无磁场条件下的阻抗值先增大后减小,说明磁场条件下试样表面的生物膜形成滞后。SEM的分析结果显示,磁场条件下Q235钢表面的生物膜均匀致密,并且紧密地黏附在金属表面。清除腐蚀产物后,无磁场条件下的基体表面呈现较多腐蚀孔和腐蚀裂缝,而有磁场条件下的基体表面则相对平整,说明磁场能有效地抑制SRB对Q235钢的腐蚀。     

HEDP-ATMP-TTA缓蚀剂对HSn70-1A铜合金腐蚀行为的影响

通过静态失重法、极化曲线法、电化学阻抗谱测定了HEDP-ATMP-TTA复配缓蚀剂在循环冷却水介质中硫酸盐还原菌(SRB)作用下对HSn70-1A铜合金的协同缓蚀作用,讨论了缓蚀剂浓度和SRB对铜合金腐蚀行为的影响.结果表明:当循环冷却水介质中加入该缓蚀剂后,可以改善SRB对HSn70-1A铜合金的侵蚀程度;随着缓蚀剂浓度的增加,合金腐蚀速率逐渐下降,缓蚀率逐渐提高.     

硫酸盐还原菌对 HSn70-1A铜合金电化学腐蚀行为的影响

用电化学、微生物学和表面分析方法研究了培养基中硫酸盐还原菌 (SRB) 对HSn70-1A 铜合金的电化学腐蚀行为,探讨了硫酸盐还原菌生物膜下介质的流动状态及材料表面状态对铜合金腐蚀的影响.结果表明,SRB的存在使电极自腐蚀电位快速负移,腐蚀速率显著增加,细菌生长后期极化电阻显著降低.扫描电子显微分析(SEM) 表明,在 SRB 作用下铜合金发生严重点蚀.介质的流动状态对细菌的附着、生长具有一定的影响,加剧了腐蚀的形成和发展.铜合金在2-巯基苯并噻唑 (MBT) 与1,2,3-苯并三氮唑 (BTA) 复配缓蚀剂中预镀膜后,耐SRB侵蚀性显著提高.     

低温超音速喷涂原态沉积高铝青铜涂层的耐腐蚀性能

为提高HSn62-1铜合金表面抗点蚀能力,解决高铝青铜涂层制备过程中相变和氧化造成涂层耐腐蚀性能降低的问题,采用低温超音速喷涂技术,在HSn62-1铜合金表面制备不含γ2相的高铝青铜涂层。利用场发射扫描电镜(SEM)、电子能谱仪(EDS)、X射线衍射仪等分析粉末和涂层的组织结构、表/截面形貌等特征;利用电化学工作站、盐雾腐蚀试验箱等测定分析Na Cl溶液环境中涂层及基体的耐腐蚀性能及失效机制。结果表明:制备的高铝青铜涂层结构致密,结合良好,无γ2相和氧化夹杂生成,涂层腐蚀敏感性均一;涂层自腐蚀电流密度为6.938μA/cm2,较HSn62-1铜合金基体降低了1个数量级,涂层自身具有较好的耐腐蚀性能,可有效阻挡腐蚀介质向涂层更深处渗入;盐雾环境中,高铝青铜涂层表面腐蚀产物薄膜反复地剥落和生成使其腐蚀失效机制宏观上表现为均匀腐蚀。     

再生水中硫酸盐还原菌对铜合金的腐蚀

采用微生物技术、表面分析技术以及电化学测量技术,研究了从再生水环境中分离提纯得到的硫酸盐还原菌(SRB)的形态、生长规律,以及SRB对铜合金HSn701-AB在再生水环境中腐蚀的影响.结果表明,在再生水环境中SRB的生长曲线存在2 d～3 d的停滞期;铜合金HSn701～AB在接种SRB的再生水环境中浸泡3 d时,出现...     

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。     

硫酸盐还原菌生物膜对HSn70－1AB铜合金电极界面的影响

测试了硫酸盐还原菌(sulfate reducing bacteria,SRB)的生长规律,浸泡初期(前 3d)SRB处于对数增长期,浸泡后期(4 d后)SRB进入稳定生长期.利用AFM技术和EIS电化学方法研究了SRB生物膜对HSn70-1AB铜合金电极界面的影响.AFM分析表明,浸泡后期合金表面生物膜粗糙度较前期有所下降.EIS结果表明,浸泡前3 d,合金表面氧化膜层较为稳定,氧化膜层电容值变化不明显.浸泡7 d后,合金表面氧化膜遭受局部腐蚀,开始出现微孔,粗糙度增加,氧化膜层电容值增大.     

X70管线钢在大庆土壤环境中微生物腐蚀行为研究

采用极化曲线、电化学阻抗谱技术和SEM、EDS、XRD分析方法研究了X70管线钢在含硫酸盐还原菌(SRB)的大庆土壤模拟溶液中的微生物腐蚀行为。结果表明,SRB在大庆土壤环境模拟溶液中生长周期分为对数生长期、衰减期和死亡期3个阶段。SRB的新陈代谢对大庆土壤环境产生显著影响:pH值在SRB生长的前2 d降低,然后呈逐渐上升趋势。氧化还原电位在SRB对数生长期降低,在衰减期和死亡期呈增加趋势。溶液电导率在SRB的对数生长期时增加,在衰减期和死亡期呈整体减小趋势。在SRB对数生长期,游离的SRB利用其新陈代谢产物H将硫酸盐还原成硫化物,促进了点蚀的发生;在SRB衰减期,腐蚀产物成团簇状,膜层致密,减缓腐蚀;在SRB死亡期,生物膜脱落,腐蚀产物膜有明显裂纹出现,形成微观腐蚀电池,导致X70管线钢的腐蚀加剧。X70管线钢在SRB的大庆土壤中腐蚀产物为FeS和Fe3O4。     

硫酸盐还原菌生物膜下Cu—Zn合金的腐蚀研究

从中原油田污水中分离提纯出硫酸还原菌（SRB）菌株,采用API RP－38推荐使用的培养基在铜材料上形成生物膜。结果表明,随着细菌的生长,细菌的代谢产物改变了黄铜的电极电位,用电子探针（EPMA）、X射线衍射（XRD）对生物膜形貌和成分进行了分析,生物膜中腐蚀产物成分主要有硫化亚铜（Cu2S)等硫化物,用交流阻抗（EIS）技术对生物膜结构进行了分析。     

Electrochemical analysis of the microbiologically influenced corrosion of steels by sulfate-reducing bacteria

The differences between the general corrosion and microbiologically influenced corrosion (MIC) of steels were investigated in terms of its electrochemical behavior and surface phenomena. The corrosion potential of steels in the absence of SRB (sulfate-reducing bacteria) shifted to a negative value with the immersion time. However, the potential of the presence of SRB shifted to a positive value after 30 days' incubation, indicating the growth of SRB biofilms on the test metal specimens and the formation of corrosion products. In addition, the color of a medium inoculated with SRB changed from gray to black. The change in color appeared to be caused by the formation of pyrites (FeS) as a corrosion product, while no significant change in color was observed in a medium without SRB inoculation. Moreover, corrosion rates of various steels tested for MIC were higher compared to those of steels in the absence of SRB. In particular, the corrosion current density of TMCP steels in the presence of SRB was larger than that of other steels. Pitting corrosion was also observed at the surface of all steels in the SRB-inoculated medium. The pitting corrosion likely occurred due to SRB that was associated with the increasing corrosion rates through increasing cathodic reactions, which caused a reduction of sulfate to sulfide as well as the formation of an oxygen concentration cell.     

Effects of benzotriazole on the corrosion of Cu10Ni alloy in sulfide-polluted salt water

Benzotriazole (BTAH) is shown to inhibit the corrosion of the Cu10Ni alloy in salt water polluted by sulfide ions. The presence of sulfide ions (at 2 ppm) decreases the inhibiting efficiency of BTAH against the corrosion of Cu10Ni alloy. This is illustrated by measurements of the integral weight loss of the alloy, its average corrosion rate and the weight of the corrosion product film over exposure times of up to 840 h. The results are interpreted in terms of competitive adsorption of the protective BTAH and the corrosion promoting sulfide ions on the alloy surface. In the presence of high concentration of BTAH, X-ray diffraction measurements revealed the absence of copper sulfide in the corrosion product film while metallographic examination revealed a much lower extent of corrosion.     

SRB 对 X70 钢在土壤模拟溶液中腐蚀行为的影响

采用失重法、SEM、EDS微观分析方法和电化学阻抗技术研究了X70钢在有/无SRB的侵蚀性土壤模拟溶液中的腐蚀行为。结果表明,在无菌介质中,X70钢表面生成不具有保护性的腐蚀产物,其腐蚀速率随浸泡时间的延长而增大;在有菌介质中,钢表面形成致密的生物膜,对界面传质有一定的阻碍作用,从而减轻X70钢的腐蚀。腐蚀产物的吸附及S含量随浸泡时间的延长而增加,使得腐蚀产物膜疏松易脱落,促进了基体的腐蚀。无菌介质中腐蚀产物内层的稳定性与腐蚀产物的沉积及分布有关;而在有菌介质中,多孔的胞外聚合物对活化过程中的质量传输过程有一定阻碍作用。     

血清白蛋白对模拟宫腔液中铜腐蚀的影响

为研究含铜宫内节育器的铜离子释放行为,在体外试验条件下考察了宫腔液中添加生化组份人血清白蛋白对铜腐蚀行为的影响。极化电阻测试的结果表明,在所研究的ＰＨ和氧分坟范围内,白蛋白总是使铜的腐蚀速度相对于无白蛋白的情况有所增大同时发现,中性条件下当白蛋白的浓度较小时,铜的腐蚀速度随白蛋白浓度的增大而增大;当白蛋白浓度大时,铜的腐蚀速度随白蛋白浓度的增大反而有所减小并趋势于一稳定值。腐蚀试验后铜试样表面ＸＲ     

含菌介质中MDOPD对SRB菌及生物膜腐蚀的抑制作用

用动电位扫描极化曲线、原子力显微镜和电子探针等方法研究了SRB生物膜在培养基介质中对于含咪唑杂环的双季铵盐化合物MDOPD的敏感性．结果表明：含菌介质中，MDOPD吸附在电极表面，形成完整致密的有机保护膜，对电极的腐蚀反应具有良好的抑制作用，SRB的代谢及腐蚀产物也难以在电极表面直接吸附和沉积，从而降低了SRB生长代谢的次生过程（包括酸浸蚀等）对腐蚀的促进作用；同时也降低了介质中的SRB参与碳钢腐蚀的机会．     

The influence of the marine aerobic Pseudomonas strain on the corrosion of 70/30 Cu–Ni alloy

A comparative study of the corrosion behavior of the 70/30 Cu–Ni alloy in a nutrient-rich simulated seawater-based nutrient-rich medium in the presence and the absence of a marine aerobic Pseudomonas bacterium was carried out by electrochemical experiments, microscopic methods and X-ray photoelectron spectroscopy (XPS). The results of Tafel plot measurements showed the noticeable increase in the corrosion rate of the alloy in the presence of the Pseudomonas bacteria as compared to the corresponding control samples. The E1S data demonstrated that the charge transfer resistance, R_ct, and the resistance of oxide film, R_f, gradually increased with time in the abiotic medium; whereas, both of them dramatically decreased with time in the biotic medium inoculated with the Pseudomonas, indicative of the acceleration of corrosion rates of the alloy. The bacterial cells preferentially attached themselves to the alloy surface to form patchy or blotchy biofilms, as observed by fluorescent microscopy (FM). Scanning electron microscopy (SEM) images revealed the occurrence of micro-pitting corrosion underneath the biofilms on the alloy surface after the biofilm removal. XPS studies presented the evolution of the passive film on the alloy surface with time in the presence and the absence of the Pseudomonas bacteria under experimental conditions, and further revealed that the presence of the Pseudomonas cells and its extra-cellular polymers (EPS) on the alloy surface retarded the formation process or impaired the protective nature of the oxide film. Furthermore, XPS results verified the difference in the chelating functional groups between the conditioning layers and the bacterial cells and the EPS in the biofilms, which was believed to connect with the loss of the passivity of the protective oxide film.     

SRB-biofilm influence in active corrosion sites formed at the steel-electrolyte interface when exposed to artificial seawater conditions

Electrochemical evolution of the interface formed by carbon steel exposed to artificial seawater with nutrients in the presence and absence of mixed cultures that contain sulfate-reducing bacteria (SRB) is characterized by electrochemical impedance spectroscopy (EIS). The artificial seawater in sterile conditions progressively covered the surface of the steel sample with two different layers after 30 days of exposure. An outer layer is formed by a mixture of chlorides and phosphorus-based iron corrosion products with organic compounds from the culture media, and an inner layer is formed by corrosion products mixture constituted mainly by phosphorus-base products. Alternatively, under biotic conditions there was one heterogeneous layer composed by a mixture of phosphorous and sulfur-based corrosion products and biofilm. Three time constants were observed with EIS for sterile conditions. At low frequencies one constant is associated with the charge transfer resistance related to the iron dissolution reaction and inversely proportional to the active area; the porous resistance magnitudes at medium frequencies characterized the physicochemical properties of the inner layer, and high frequency described the electrical properties of the outer mixture layer. Low carbon steel in the presence of SRB (halophilic hydrogenotrophic) showed the impedance distribution after the formation of a corrosion product thick black layer mixed with organic composites and bio-entities. The SRB-biofilm enhanced the corrosion rate and influenced the appearance of diffusion controlled mechanism process. Electrical passive analogs in terms of constant phase elements characterized the evolution of the cover films formed and the impedance of the layers with time. The mechanisms are characterized based on the impedance response for three time constants in the absence of SRB and one time constant with a finite Warburg element when SRB are present in the electrolyte. The validation of the theoretical approximation with electrical analogs was in good agreement with the experimental results.