海泥中SRB对纯锌阳极腐蚀行为的影响

测量锌阳极在海泥和含硫酸盐还原菌(SRB)海泥中构成的宏电池中的腐蚀,研究了SRB对海泥中纯锌阳极材料的腐蚀行为的影响.结果表明,SRB能快速破坏纯锌的表面钝化膜,提高锌阳极在海泥中的自腐蚀速率。在含SRB和无SRB海泥构成的宏电池体系中,含菌海泥中的锌试样为电偶对的阳极,腐蚀增大;无菌海泥中的试样为电偶对的阴极,腐蚀受到抑制。     

高矿化度油田卤水中pH值对20碳钢在硫酸盐还原菌作用下腐蚀行为的影响

目前对含硫酸盐还原菌(SRB)高矿化度下油气田卤水的腐蚀行为报道较少.采用挂片腐蚀试验和电化学试验法研究了20碳钢在含硫酸盐还原菌的不同pH值高矿化度油田卤水中的腐蚀规律,采用扫描电镜观察试样形貌.结果表明:20碳钢在pH值为5.5的含SRB腐蚀液中的腐蚀较pH值为7.5时严重,是不含SRB腐蚀液中的6倍多;pH值为7.5时,20碳钢表面微生物膜较厚,碳钢的腐蚀速率有所下降,致密的SRB生物膜的形成对溶液中Cl-的迁移起到了阻碍作用,碳钢的腐蚀得到了一定的抑制.     

海洋硫酸盐还原菌对Q235钢腐蚀行为的影响

采用失重法、开路电位、电化学阻抗谱(EIS)、极化曲线等方法,通过在海洋环境中浸泡不同时间对比分析有无硫酸盐还原菌(SRB)条件下Q235钢的腐蚀电化学特征,研究SRB对Q235钢的腐蚀行为的影响。结果表明,在含SRB的海水中,随着浸泡时间延长,Q235钢的腐蚀电流密度先从7.49mA·cm~(-2)增加至9.77mA·cm~(-2),然后逐渐减小至5.01mA·cm~(-2),最终增加至12.6mA·cm~(-2),且始终小于相同时间下无SRB海水中的腐蚀电流密度,表明SRB的存在抑制了Q235的腐蚀。在含SRB的海水中,Q235钢的腐蚀行为主要由Cl~-和生物膜共同影响。在SRB稳定生长阶段,腐蚀以生物膜抑制为主;在SRB指数生长阶段和衰亡阶段,生物膜抑制作用较弱,以Cl~-促进金属腐蚀为主。     

海滨盐碱土壤中硫酸盐还原菌对X100管线钢腐蚀行为的影响

为了进一步明确X100管线钢在含硫酸盐还原菌(SRB)海滨盐碱土壤中的耐蚀性,采用表面分析技术、电化学技术和失重法,研究了SRB对X100管线钢腐蚀过程与行为的影响。结果表明:X100管线钢在有无SRB海滨盐碱土壤中的腐蚀均属于中度腐蚀,无SRB时腐蚀产物主要为Fe_2O_3,Fe_3O_4和γ-Fe O(OH),有SRB时腐蚀产物主要为Fe_2O_3,Fe_3O_4,α-Fe O(OH)和Fe7S8;SRB代谢形成的活性生物膜影响了X100管线钢的腐蚀行为,随着腐蚀时间的增加,SRB可在X100管线钢表面形成由微生物膜与腐蚀产物结合的膜,其更加致密,对腐蚀传质具有物理阻碍作用,可以减缓X100管线钢的腐蚀;无SRB菌时X100管线钢表面的腐蚀产物疏松多孔并分布有裂纹,且对基体的保护作用差,其腐蚀速率大于有SRB时的值;SRB的代谢活动抑制了X100管线钢的腐蚀。     

A3钢在庆氧环境中的微生物腐蚀电化学特性研究

用交流阻抗法、动电位扫描法研究了A3钢在无菌培养液和培养液加硫酸盐还原菌的厌氧体系中的腐蚀行为。实验结果表明：硫酸盐还原菌(简称SRB)参与了A3钢的电化学行为，在SRB参与的腐蚀过程中，SRB加速A3钢的腐蚀，它对A3钢的阳极极化过程影响很大，而对阴极过程影响很小     

SRB对X70管线钢在喷气燃料中腐蚀行为的影响

目前,关于油水体系中微生物的腐蚀形成过程、腐蚀机理、检测和评价手段、影响因素以及腐蚀控制方法等研究尚不成熟。采用失重法、线性极化曲线和电化学阻抗谱技术,结合扫描电子显微镜(SEM)和能谱分析仪(EDS)研究了X70管线钢在含硫酸盐还原菌(SRB)的喷气燃料中的腐蚀行为。结果表明:X70管线钢在无菌介质中的腐蚀类型为局部腐蚀;在有菌介质中腐蚀比较严重,出现大面积溃疡状腐蚀区域并伴有大量鼓泡现象,浸泡初期腐蚀速率最大,随着浸泡时间的延长,腐蚀仍然在进行,但腐蚀速率有所下降,SRB参与并促进了X70管线钢的腐蚀,加速阴极反应,增大了X70管线钢的腐蚀倾向。     

X100管线钢在库尔勒土壤模拟溶液中的微生物腐蚀特征

采用线性极化曲线和交流阻抗技术(EIS)结合扫描电子显微镜和能谱分析仪,研究了SRB对X100管线钢在库尔勒土壤模拟溶液中腐蚀行为的影响。实验结果表明:X100管线钢在无菌与含SRB模拟溶液中的腐蚀均属于中度腐蚀;SRB加剧了X100管线钢在库尔勒土壤中的腐蚀,但在浸泡17~35d过程中,微生物膜与腐蚀产物结合成的复合膜会在短时间内发生急剧抑制腐蚀作用;X100管线钢在无菌模拟溶液中的腐蚀倾向为随时间延长先减小后增大,含SRB时为先减小后增大再减小,腐蚀速率在无菌与含SRB模拟溶液中时均为随时间延长先减小后增大。     

X100管线钢在库尔勒土壤模拟溶液中的微生物腐蚀特征

采用线性极化曲线和交流阻抗技术(EIS)结合扫描电子显微镜和能谱分析仪,研究了SRB对X100管线钢在库尔勒土壤模拟溶液中腐蚀行为的影响。实验结果表明:X100管线钢在无菌与含SRB模拟溶液中的腐蚀均属于中度腐蚀;SRB加剧了X100管线钢在库尔勒土壤中的腐蚀,但在浸泡17~35d过程中,微生物膜与腐蚀产物结合成的复合膜会在短时间内发生急剧抑制腐蚀作用;X100管线钢在无菌模拟溶液中的腐蚀倾向为随时间延长先减小后增大,含SRB时为先减小后增大再减小,腐蚀速率在无菌与含SRB模拟溶液中时均为随时间延长先减小后增大。     

硫酸盐还原菌生物膜下BFe30-1-1铜合金的腐蚀行为

硫酸盐还原茵是最重要的生物腐蚀茵,对凝汽器传热管的腐蚀较为严重.采用电化学方法、微生物学方法和表面分析方法,在培养基中就硫酸盐还原茵(简称SRB)对凝汽器传热管材料BFe30-1-1铜合金的腐蚀电化学行为进行了研究.结果表明:SRB的存在使电极自腐蚀电位剧烈负移,腐蚀速率显著增加,极化电阻在细菌生长后期显著降低,在SRB作用下BFe30-1-1铜合金发生了严重点蚀.     

升温时效处理7075铝合金在含SRB模拟海水中的应力腐蚀行为

7系铝合金是一种可热处理强化的铝合金,通过改变热处理工艺的方法可以提高铝合金的抗应力腐蚀性能.本文研究了不同升温时效处理下,铝合金在含硫酸盐还原菌(SRB)模拟海洋溶液中的应力腐蚀行为,并通过应力-应变曲线和断口形貌,对比分析了铝合金在无菌溶液和SRB溶液中的应力腐蚀行为差异.研究表明,升温时效处理可以提高合金的自腐蚀...     

Characterization and corrosion behavior of electroless Ni–P/nano-SiC coating inside the CO2 containing media in the presence of acetic acid

In this research, Ni–P and Ni–P/nano-SiC coatings were applied on the X70 steel substrate successfully without any surfactant. Then, CO₂ corrosion in the presence of acetic acid (HAc) was investigated using electrochemical techniques. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) techniques were used for surface analyses of the coatings. The electrochemical behavior of corrosion was investigated using polarization test and electrochemical impedance spectroscopy (EIS). XRD pattern of Ni–P/nano-SiC coating was very similar to that of Ni–P coating. EDS results demonstrated the presence of SiC particles in the coating. SEM images confirmed the presence of SiC nano-particles with almost uniform distribution in the coating. The corrosion current density was less in the Ni–P and Ni–P/nano-SiC coated samples than uncoated X70 steel. Ni–P/nano-SiC coated sample had the most corrosion resistance because of less effective metallic area available for corrosive media. The overall protection mechanism of Ni–P and Ni–P/nano-SiC coatings was achieved by formation of a layer of adsorbed hypophosphite anions (H₂PO₂⁻).     

Localized corrosion behavior of 316L stainless steel in the presence of sulfate-reducing and iron-oxidizing bacteria

Localized corrosion behavior of 316L stainless steel was investigated in the presence of sulfate-reducing bacteria (SRB) and iron-oxidizing bacteria (IOB) isolated from cooling water system using polarization measurement, scanning electron microscopy (SEM) examinations and energy dispersive spectrum (EDS) analysis. The results show the corrosion potential (E_corr) and breakdown potential (E_b) of SS decreased in turn with the presence of IOB, SRB and SRB + IOB, indicating decreased relative resistance to localized corrosion. E_corr in the sterile medium remained virtually unchanged with exposure time, indicating that localized attack did not occur. However, micrometer-scale pitting was observed on the SS surface in the presence of bacteria. The presence of SRB demonstrated higher corrosion rates than IOB. The combination of SRB and IOB yielded the highest corrosion rate. The presence and metabolic activities of bacteria on SS surface produce environments that can alter rates of partial reactions in corrosion processes and shift corrosion mechanisms. The most severe microbiologically induced corrosion takes place in aquatic solution where physiological groups of aerobic and anaerobic microorganisms interact.     

海泥中硫酸盐还原菌对1Cr13不锈钢腐蚀的影响

利用交流阻抗测试技术，扫描电镜及表面能谱、失重法、微生物分析等方法，在室内模拟条件下研究了海泥中硫酸盐还原菌对1Cr13不锈钢腐蚀的影响，及在含和不含硫酸盐还原菌的海泥构成的宏电池腐蚀中1Cr13不锈钢的腐蚀行为。试验结果表明，在有菌泥中1Cr13不锈钢的自然腐蚀速度均大于在灭菌泥中，两相差5．1倍。说明海泥中硫酸盐还原菌增大了1Cr13不锈钢的腐蚀速率。在有菌和灭菌海泥构成宏电池时，有菌海泥中1Cr13不锈钢作为阳极，腐蚀速率比自然腐蚀状态下有所增大，加速率为14．6％。而在灭菌海泥中1Cr13不锈钢作为阴极，腐蚀速率比自然腐蚀状态下有所减小。     

Zn-Al-Mg-RE涂层在含SRB海水中的耐腐蚀性与机理

利用高速电弧喷涂技术在Q235钢基体上制备Zn-Al-Mg-RE涂层,采用环氧改性有机硅树脂对涂层进行封孔,在含硫酸盐还原菌(SRB)海水中浸泡后,采用EIS,PC等方法研究Zn-Al-Mg-RE涂层在SRB一个生长周期内的腐蚀行为,并对涂层进行表面微观形貌和化学成分分析,探讨其腐蚀机理。结果表明:封孔和未封孔的Zn-Al-Mg-RE涂层在含SRB海水中的腐蚀速率均呈先增大后减小的趋势;封孔后Zn-Al-Mg-RE涂层的耐腐蚀性得到较大提高。经过浸泡后的Zn-Al-Mg-RE涂层表面覆盖了一层微生物和腐蚀产物组成的混合物层和钝化膜层,避免了涂层进一步遭受损坏。     

Interaction between sulfate-reducing bacteria and aluminum alloys——Corrosion mechanisms of 5052 and Al-Zn-In-Cd aluminum alloys

Microbiologically influenced corrosion caused by sulfate-reducing bacteria(SRB) poses a serious threat to marine engineering facilities.This study focused on the interaction between the corrosion behavior of two aluminum alloys and SRB metabolic activity.SRB growth curve and sulfate variation with and with aluminum were performed to find the effect of two aluminum alloys on SRB metabolic activity.Corrosion of 5052 aluminum alloy and Al-Zn-In-Cd aluminum alloy with and without SRB were performed.The results showed that both the presence of 5052 and Al-Zn-In-Cd aluminum alloy promoted SRB metabolic activity,with the Al-Zn-In-Cd aluminum alloy having a smaller promotion effect compared with 5052 aluminum alloy.The electrochemical results suggested that the corrosion of the Al-Zn-In-Cd aluminum alloy was accelerated substantially by SRB.Moreover,SRB led to the transformation of Al-Zn-In-Cd aluminum alloy corrosion product from Al(OH)3 to Al2 S3 and NaAlO2.     

The shielding effect of wild type iron reducing bacterial flora on the corrosion of linepipe steel

Microbiologically influenced corrosion (MIC) by microbes capable of iron reduction (iron reducing bacteria (IRB)) on API 5L ×52 carbon steel coupons was investigated. A wild type of IRB was isolated and cultivated from a water sample collected from a sour oil well located in Louisiana, USA. 16S rRNA gene sequence analysis indicated that the mixed bacterial consortium contained two phylotypes close to members of the Proteobacteria (Shewanella oneidensis sp.) and Firmicutes (Brevibacillus sp.). The corrosion behavior of carbon steel coupons exposed to different media, with and without these microbes, was characterized by open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and polarization resistance (R_p), and a corrosion mechanism has been proposed. The biofilm and pit morphology that developed with time were characterized using field emission scanning electron microscopy (FESEM). Interestingly, surface morphology and electrochemical evaluations confirmed that IRB metabolic activities and resulting biofilms inhibit the corrosion process. The maximum corrosion rate in the biotic system was 4 mpy, while it was 20 mpy in the abiotic solution. Minor isolated pits were revealed in the biotic system, whereas extensive general pitting was found in the abiotic system. Elemental analysis and corrosion product structures were characterized by energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). XRD confirmed the formation of a significant amount of iron oxide compounds that include iron, Hematite (Fe₂O₃), Magnetite (Fe₃O₄) and iron (II) hydroxide Fe(OH)₂ on the steel surface exposed to a biotic system.