新型耐微生物腐蚀油管钢的硫酸盐还原菌腐蚀行为研究
SRB Induced Corrosion Behavior of a Novel Microbial Corrosion Resistant Pipeline Steel
通讯作者: 闫茂成,E-mail:yanmc@imr.ac.cn,研究方向为油气材料腐蚀及控制
收稿日期: 2025-02-21 修回日期: 2025-05-30
| 基金资助: |
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Corresponding authors: YAN Maocheng, E-mail:yanmc@imr.ac.cn
Received: 2025-02-21 Revised: 2025-05-30
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作者简介 About authors
杨宝齐,男,1984年生,本科
通过形貌观察、成分分析、微生物分析及电化学测试等方法,研究耐微生物腐蚀(MIC)油管钢的硫酸盐还原菌(SRB)腐蚀行为。结果表明:SRB环境中耐MIC钢表面附着的活跃细菌数量大幅减少,生物膜厚度减小,耐MIC钢有效抑制了表面生物膜的附着生长;耐MIC钢具有更高的自腐蚀电位、更低的腐蚀电流密度和更大的电荷转移电阻;耐MIC钢表面腐蚀产物少,主要为致密的α-FeOOH,而普通钢表面则以疏松的Fe3O4为主,普通钢的失重腐蚀速率约为耐MIC钢的1.83倍,通过优化Cu-Cr-Ni三元合金体系,所制备的油管钢抗菌与耐蚀性能均提升。
关键词:
The corrosion behavior of a microbial corrosion-resistant (MIC-resistant) pipeline steel induced by sulfate reducing bacteria (SRB) was investigated through morphology observation, composition analysis, microbial culture analysis and electrochemical testing. The results show that, in the SRB environment, the number of active bacteria adhered to the surface of MIC-resistant steel is significantly reduced, and accordingly the thickness of the biofilm decreases. The MIC-resistant steel effectively inhibits biofilm attachment and growth on its surface. The MIC-resistant steel exhibited higher open-circuit potential, lower corrosion current density, and higher charge transfer resistance. There are fewer corrosion products on the surface of the MIC-resistant steel, composed mainly of dense α-FeOOH scale, in the contrast, a loose Fe3O4 scale may emerge on the ordinary steel surface. The corrosion rate in mass loss of an ordinary steel is approximately 1.83 times that of the MIC-resistant steel. It follows that comprehensively optimizing the content of the three alloying elements Cu, Cr, and Ni, synergistic improvement in both anti-bacterial and anti-corrosion could be achieved for this novel steel.
Keywords:
本文引用格式
杨宝齐, 闫茂成, 史显波, 高博文.
YANG Baoqi, YAN Maocheng, SHI Xianbo, GAO Bowen.
开发和使用抗菌管线钢是解决微生物腐蚀问题的有效途径之一。通过在管线钢中加入一定比例的抗菌合金元素(如Cu、Ag等),赋予其抗菌性能,成为抑制微生物腐蚀的新思路。目前,中国科学院金属研究所、衡阳钢管和上海宝钢等机构均有开展耐微生物腐蚀(MIC)管线钢材料研究开发和推广应用工作[3~7]。Cu2+可通过破坏微生物细胞膜和DNA复制机制,使材料具有一定耐MIC性能,可作为关键合金元素加入管线钢中,同时适当调整Cr、Ni等元素含量,进一步优化管道钢的综合性能[8]。其中,Cr在钢表面形成的富铬层也可以有效阻止微生物腐蚀的发生,Cr和Cu协同提高管道钢耐微生物腐蚀性能[9]。于浩波等[10]在L245NCS管线钢中添加0.61% (质量分数,下同)的Cu,含Cu管线钢显著减弱了细菌的生长活性,抑制了点蚀发生,降低腐蚀速率。曾云鹏等[11]研究表明,Cu显著提高了管线钢的耐微生物腐蚀性能。Cu的含量对其耐微生物腐蚀性能具有重要影响。Cu含量越高耐蚀性能越强,在含SRB环境下,当Cu含量达到1.34%时可显著抑制管线钢的微生物腐蚀。尽管含Cu管线钢的抗菌性能已被广泛认可,但现有研究仍存在显著局限。单一依赖Cu抗菌的普适性方案难以兼顾材料加工性能,当Cu含量超过1.0%时,可能形成析出相,影响钢的加工性能,如焊接性。当Cu含量从1.0%提高到2.0%时其-20 ℃的冲击功将降低2/3[12]。传统防腐策略侧重单一功能优化,忽视环境适应性需求。微生物腐蚀涉及多因素耦合作用,仅通过单一元素改性难以实现长效防护。
本工作通过Cu-Cr-Ni三元合金体系优化制备了一种新型耐微生物腐蚀钢,采用极化曲线和电化学阻抗谱(EIS)等电化学测量技术,结合扫描电镜(SEM)、Raman光谱和激光共聚焦显微镜(CLSM)等表面形貌分析技术,通过与普通钢对比分析,研究耐MIC油管钢的SRB腐蚀行为,为油田管道的设计和选材提供依据。
1 实验方法
表1 实验用钢的化学成分
Table 1
| Sample | C | Si | Mn | P | S | Cu | Cr | Ni | Mo | Fe |
|---|---|---|---|---|---|---|---|---|---|---|
| Ordinary steel | 0.14 | 0.25 | 1.2 | 0.02 | 0.01 | 0.40 | 0.40 | 0.40 | 0.14 | Bal. |
| MIC resistant steel | 0.07 | 0.18 | 0.3 | 0.007 | 0.002 | 0.55 | 1.40 | 0.55 | 0.14 | Bal. |
图1
图1
耐MIC钢和普通油管钢的显微组织
Fig.1
Microstructures of ordinary steel (a) and MIC resistant steel (b)
腐蚀失重试样尺寸为50 mm × 10 mm × 3 mm,电化学测量试样尺寸为10 mm × 10 mm × 3 mm。电化学试样背面连接Cu导线,采用环氧树脂密封。各试样使用水磨砂纸逐级打磨至1000目,去离子水冲洗,酒精脱水,冷风干燥,置于干燥皿中备用。
实验所用SRB采集自油田集输管道内腐蚀产物,通过API RP-38培养基富集培养获得。实验溶液采用API RP-38培养基,其成分为:NaCl 15.0 g/L,MgSO4·7H2O 0.2 g/L,乳酸钠4.0 g/L,酵母膏1.0 g/L,K2HPO4 0.5 g/L,抗坏血酸0.1 g/L,并用1 mol/L的NaOH溶液调节pH值7.0~7.2,通2 h氮气除氧。使用高压灭菌锅或紫外灯照对实验体系中所用的溶液、容器、电极等进行灭菌处理。实验开始时将3%的SRB菌种接种入实验溶液环境中。
微生物腐蚀浸泡实验在35 ℃恒温水浴锅中进行,周期14 d。实验过程中,采用Gamry 600+电化学工作站测量EIS极化曲线。电化学测试采用三电极系统,辅助电极为铂网电极,参比电极为饱和甘汞电极(SCE)。EIS测试在开路电位下进行,以10 mV正弦交流电作为EIS的激励信号,测试频率105~10-2 Hz,数据使用Zsimpwin软件拟合分析。极化曲线扫描速率采用0.5 mV/s。实验介质中的SRB数量采用琼脂平板法(GB 4789.2-2022)计数。
实验结束后,分析两种材料试样表面微生物膜/腐蚀产物形貌和成分,观察试样腐蚀形貌特征,计算平均腐蚀速率。采用Invia Reflex Raman光谱仪分析腐蚀产物成分,测试激光波长532 nm,物镜50倍,光束直径2 μm,实测光谱范围200~1500 cm-1。
采用荧光染色法观察浸泡实验试样表面附着的细菌活/死状态,分析两种材料抗菌性能。荧光染色试样在核酸荧光染料中避光染色15 min后,用磷酸缓冲盐溶液(PBS)冲洗浮色,使用FV3000型激光共聚焦显微镜观察试样表面细菌的活/死状态及分布情况。
为观察试样表面生物膜形貌,需进行固化及脱水处理,将试样浸泡在含3%戊二醛的PBS中,固化30 min后,用无菌PBS溶液和去离子水浸泡清洗。清洗后使用50%、70%、95%和99%的乙醇进行逐级脱水处理各10 min,脱水后迅速吹干。采用XL30-FEG型SEM观察试样表面腐蚀产物形貌和生物膜特征,使用SEM自带的能谱仪(EDS)分析表面腐蚀产物成分。
使用除锈液(500 mL盐酸+500 mL H2O + 3.5 g六次甲基四胺)去除试样表面腐蚀产物,利用SEM观察去除腐蚀产物后试样表面形貌,利用LSM700 CLSM观察试样表面的点蚀坑形貌及深度,并计算试样腐蚀速率。
式中,v为腐蚀速率(mm/a),W0为实验前试样的质量(g),W为实验后试样的质量(g),S为试样暴露面积(cm2),t为浸泡时间(h),ρ为管材密度(g·cm-3)。
2 结果与讨论
2.1 腐蚀产物形貌及成分分析
在含SRB环境中浸泡14 d后试样宏观形貌显示,普通钢表面呈黑色,耐MIC钢表面颜色稍浅,呈深棕色,部分位置呈黄色。去除腐蚀产物后试样表面仍可见砂纸研磨痕迹,普通钢表面可见少量腐蚀坑。通过失重分析,耐MIC钢和普通钢失重腐蚀速率分别为0.0098和0.0179 mm/a,普通钢失重腐蚀速率约为耐MIC钢失重腐蚀速率的1.83倍。
图2
图2
接菌培养基中浸泡14 d后耐MIC钢和普通钢表面腐蚀产物SEM形貌及EDS分析
Fig.2
SEM surface morphologies (a-d) and EDS analysis results (e, f) of MIC resistant steel (a, b, e) and ordinary steel (c, d, f) after 14 d immersion in SRB inoculated solution
耐MIC钢和普通钢两种试样表面腐蚀产物的Raman图谱(图3)显示,680 cm-1附近的谱峰为Fe3O4,390和1300 cm-1附近为α-FeOOH,215和280 cm-1附近为FeS,1080 cm-1附近为FeCO3。由此可知,在SRB腐蚀过程中,SO
图3
图3
耐MIC钢和普通钢在接菌培养基中浸泡14 d后表面Raman图谱
Fig.3
Raman spectra of the surfaces of MIC resistant steel and ordinary steel after 14 d immersion in SRB inoculated solution
2.2 生物膜观察
实验开始时和结束后溶液中微生物数量分别为5000和150000 cfu/mL,SRB在溶液中大量繁殖。图4为耐MIC钢和普通钢在接种SRB培养基中浸泡7 d后两种材料表面活/死染色后的CLSM图。荧光染色后金属表面微生物膜可显示出不同的颜色,图中绿色点表示活细菌附着,黄色和红色点表示损伤细菌和杀死细菌。普通钢(图4a)表面附着大量的绿色活跃细菌,仅存在少量红色死亡细菌,生物膜厚度为63.04 μm;而耐MIC钢(图4b)表面大部分为红色死亡和黄色损伤细菌,活细菌数量大幅减少,SRB的附着位点减少,大量死亡细菌形成了死亡微生物层,厚度约为51.22 μm。相比于普通钢,耐MIC钢表面活跃SRB减少,明显抑制了表面生微物膜的形成。腐蚀过程中Fe2+主要被HS-消耗,阻碍了FeOOH向Fe3O4的转化,使得耐MIC钢中α-FeOOH为最强谱峰。两种材料试样表面生物膜测试结果与除锈后表面的腐蚀程度对应,再次说明生物膜附着生长对微生物腐蚀过程影响显著。
图4
图4
耐MIC钢和普通钢在接菌培养基中浸泡7 d后的CLSM像
Fig.4
CLSM images of MIC resistant steel (a) and ordinary steel (b) after 7 d immersion in SRB inoculated solution
2.3 腐蚀形貌分析
图5
图5
耐MIC钢和普通钢在接菌培养基中浸泡14 d,去除腐蚀产物后的表面形貌
Fig.5
SEM surface morphologies of ordinary steel (a-c) and MIC resistant steel (d-f) after removal of corrosion products formed during 14 d immersion in SRB inoculated solution
图6
图6
耐MIC钢和普通钢在接菌培养基中浸泡14 d后表面最大点蚀形貌
Fig.6
Surface maximum pitting morphologies of MIC resistant steel (a) and ordinary steel (b) after 14 d immersion in SRB inoculation solution
2.4 电化学测试
图7
图7
耐MIC钢和普通钢在接菌培养基中浸泡14 d后的动电位极化曲线
Fig.7
Potentiodynamic polarization curves of MIC resistant steel and ordinary steel after 14 d immersion in SRB inoculation solution
表2 耐MIC钢和普通钢在接菌培养基中浸泡14 d后的动电位极化曲线拟合参数
Table 2
| Steel | βa / mV·dec-1 | βc / mV·dec-1 | Icorr / μA·cm-2 | Ecorr / mV | Corrosion rate / mm·a-1 |
|---|---|---|---|---|---|
| Ordinary steel | 346 | 102 | 14.9 | -888 | 0.173 |
| MIC resistant steel | 243 | 76.3 | 8.53 | -847 | 0.0992 |
图8是耐MIC钢和普通钢在接菌培养基中浸泡35 d的EIS谱的Bode和Nyquist图。结果显示,所有试样测量的阻抗曲线在整个频率范围内显示出完整的容抗弧,未出现扩散特征,表面浸泡过程中试样电化学过程处于电荷转移控制。耐MIC钢容抗弧半径均大于普通钢,表明耐MIC钢电化学过程受到抑制,表现出更好的耐蚀性能。高频阻抗(|Z|HF)和低频阻抗(|Z|LF)分别表示溶液电阻和电荷转移电阻,|Z|LF与腐蚀速率呈负相关。浸泡过程中,耐MIC钢的|Z|LF低于普通钢的。普通钢相角峰值升高并向低频区移动,表明表面腐蚀产物不断积累。耐MIC钢2 d后相角出现两个峰,表明存在两个时间常数,产生此现象的原因可能是,附着在表面的SRB被耐MIC钢所杀死,死亡的微生物在表面形成了一层死亡微生物层。
图8
图8
耐MIC钢和普通钢在接菌培养基中浸泡不同时间后的Nyquist和Bode图
Fig.8
Nyquist (a, c) and Bode (b, d) plots of MIC resistant steel (a, b) and ordinary steel (c, d) after immersion in SRB inoculated solution for different time
图9
图9
用于EIS拟合的等效电路模型
Fig.9
Equivalent circuit model used to fit EIS data (Rs-solution resistance, Qbc-biofilm and corrosion product layer capacitance, Rbc-biofilm and corrosion product layer resistance, Qct-interface double-layer capacitance, Rct-metal surface charge transfer resistance)
表3 接菌培养基中的EIS拟合结果
Table 3
| Samples | Time / d | Rs / Ω·cm2 | Rbc / Ω·cm2 | Qbc / Ω-1·cm-2·s n | Rct / Ω·cm2 | Qct / Ω-1·cm-2·s n |
|---|---|---|---|---|---|---|
| Ordinary steel | 1 | 3.64 | 8008 | 5.82 × 10-4 | 52.97 | 1.43 × 10-3 |
| 2 | 3.52 | 9103 | 3.12 × 10-3 | 0.258 | 1.73 × 10-2 | |
| 4 | 3.61 | 3311 | 3.79 × 10-3 | 483 | 1.20 × 10-2 | |
| 7 | 3.87 | 4671 | 6.44 × 10-3 | 2930 | 4.01 × 10-3 | |
| 10 | 3.81 | 2045 | 6.39 × 10-3 | 3114 | 4.87 × 10-3 | |
| 14 | 3.87 | 1019 | 6.34 × 10-3 | 7339 | 6.29 × 10-3 | |
| MIC resistant steel | 1 | 3.56 | 0.11 | 5.09 × 10-4 | 2.31×104 | 6.01 × 10-4 |
| 2 | 3.62 | 692 | 2.02 × 10-3 | 27.91 | 6.14 × 10-3 | |
| 4 | 3.47 | 24.5 | 1.02 × 10-2 | 269 | 3.70 × 10-3 | |
| 7 | 3.55 | 8.26 | 3.71 × 10-3 | 1.66 × 104 | 2.83 × 10-3 | |
| 10 | 3.59 | 38.2 | 3.23 × 10-3 | 1.37 × 104 | 2.93 × 10-3 | |
| 14 | 3.65 | 36.3 | 3.52 × 10-3 | 5.66 × 104 | 2.10 × 10-3 |
金属和液膜界面的双电层与生物膜和腐蚀产物层是影响电极反应过程的状态变量。电化学体系的极化电阻Rp可用拟合参数Rct + Rbc表示。Rp反映电极反应时的阻力大小,与腐蚀速率成反比。由Rct + Rbc随时间的变化(图10)可见,实验初期(前7 d)试样腐蚀速率较高,普通钢与耐MIC钢差别较小。7 d后,普通钢保持较高腐蚀速率,而耐MIC钢腐蚀速率出现明显下降,腐蚀电化学过程被显著抑制。
图10
图10
耐MIC钢和普通钢在接菌培养基中Rct + Rbc随时间的变化曲线
Fig.10
Variations of Rct + Rbc of MIC resistant steel and ordinary steel with immersion time in SRB inoculated solution
2.5 讨论
活/死生物膜染色表明,耐MIC钢表面大部分为红色死亡和黄色损伤细菌,活跃细菌数量大幅减少,SRB的附着位点减少;电化学测试表明,耐MIC钢表现出更高的自腐蚀电位、更小的腐蚀电流密度和更大的电荷转移电阻;耐MIC钢的失重腐蚀速率明显低于普通钢。这些结果均表明,与普通管道钢对比,耐MIC油管钢耐SRB腐蚀性能明显。
Cu可抑制管道钢表面SRB的生长及生物膜的形成。一方面,含Cu钢表面在环境介质中释放Cu2+ [18]。Cu2+可与微生物细胞膜上带负电基团(如磷脂、蛋白质等)结合,减少生物膜中的蛋白质和多糖含量,改变蛋白质的结构和功能,增加细胞膜的通透性,使细胞内的物质外流,导致细胞死亡[19]。Cu2+进入细菌会促进过氧化氢(H2O2)、超氧阴离子(O
3 结论
(1) 普通钢在接种SRB的培养基中腐蚀更为严重,表面存在大量腐蚀坑,腐蚀产物主要为Fe的氧化物和S的化合物,且表面O和S含量明显大于耐MIC钢。最强Raman光谱峰为结构相对疏松的Fe3O4,易使腐蚀性介质渗透到金属基体表面引发进一步腐蚀。普通钢表面同时发生点蚀和均匀腐蚀,且附着大量活跃细菌,生物膜更厚,厚度为63.04 μm。
(2) 耐MIC钢在各方面表现出更好的抗腐蚀性能,其失重腐蚀速率更低,表面仅有少量疏松的絮状腐蚀产物,最强Raman光谱峰为致密锈层的α-FeOOH,能阻止腐蚀性介质渗入。耐MIC钢抑制了生物膜的形成,表面仅存在零星小而浅的点蚀坑,且在电化学测试中表现出更高的自腐蚀电位、更小的腐蚀电流密度和更大的电荷转移电阻。
(3) 耐MIC钢在SRB环境中具有更好的抗微生物腐蚀性能,表面活跃细菌数量大幅减少,大部分为红色死亡和黄色损伤细菌,生物膜厚度减少,显示出抑制生物膜形成的作用。
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Novel Cu-bearing pipeline steels: a new strategy to improve resistance to microbiologically influenced corrosion for pipeline steels
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新型含Cu管线钢——提高管线耐微生物腐蚀性能的新途径
[J].
Study on microbiologically influenced corrosion behavior of novel Cu-bearing pipeline steels
[J].
新型含Cu管线钢的微生物腐蚀行为研究
[J].
Study on microbiologically influenced corrosion of HSLA-65 steel
[J].
Properties and application of antibacterial stainless steels
[J].
抗菌不锈钢的性能与应用
[J].
Microbiologically influenced corrosion of Cu-bearing steel welded joints for petroleum pipes
[J].
石油管材用含Cu钢焊接接头的微生物腐蚀研究
[J].
Copper alloying improves the microbiologically influenced corrosion resistance of pipeline steel
[J].
Microbiologically influenced corrosion of a novel pipeline steel containing Cu and Cr elements in the presence of Desulfovibrio vulgaris Hildenborough
[J].
Anti microbiological corrosion performance of Cu-containing antibacterial pipeline steel
[J].
含Cu抗菌管线钢的抑制微生物腐蚀性能
[J].
Effect of copper content on the MIC resistance in pipeline steel
[J].
Cu含量对管线钢耐微生物腐蚀性能的影响
[J].
Microbial corrosion resistance of a novel Cu-bearing pipeline steel
[J].
SRB-mediated corrosion of marine submerged AISI 1020 steel under impressed current cathodic protection
[J].
Synergistic inhibition of rhamnolipid and 2, 2-dibromo-3-hypoazopropionamide on microbiologically influenced corrosion of X80 pipeline steel
[J].
鼠李糖脂与2,2-二溴-3-次氮基丙酰胺协同抑制X80管线钢的微生物腐蚀
[J].
Corrosion resistance and biocompatibility of calcium-containing coatings developed in near-neutral solutions containing phytic acid and phosphoric acid on AZ31B alloy
[J].
Corrosion behavior of high entropy alloy FeNiCoCrW0.2Al0.1 in sulfate-reducing bacteria containing solution
[J].
FeNiCoCrW0.2Al0.1高熵合金在硫酸盐还原菌溶液环境下的腐蚀研究
[J].
Effect of crevice morphology on SRB activity and steel corrosion under marine foulers
[J].
Enhanced the SRB corrosion resistance of 316L stainless steel via adjusting the addition of Cu and Ce elements
[J].
Antibacterial behavior and related mechanisms of martensitic Cu-bearing stainless steel evaluated by a mixed infection model of Escherichia coli and Staphylococcus aureus in vitro
[J].
Free radicals and oxidative stress in bacteria
[J].
Application of copper to prevent and control infection. Where are we now?
[J].
Study on the antibacterial mechanism of Cu-bearing titanium alloy in the view of materials science
[J].
Effect of nano/micro-Ag compound particles on the bio-corrosion, antibacterial properties and cell biocompatibility of Ti-Ag alloys
[J].
The iron-sulfur clusters of dehydratases are primary intracellular targets of copper toxicity
[J].
Antibacterial Ti-Cu implants: A critical review on mechanisms of action
[J].
What controls the antibacterial activity of Ti-Ag alloy, Ag ion or Ti2Ag particles?
[J].
Study on antibacterial mechanism of copper-bearing austenitic antibacterial stainless steel by atomic force microscopy
[J].
Toward a molecular understanding of the antibacterial mechanism of copper‐bearing titanium alloys against Staphylococcus aureus
[J].
Research progress of metal corrosion caused by extracellular polymeric substances of microorganisms
[J].
微生物胞外聚合物引起的金属腐蚀的研究进展
[J].
Contact killing of Cu-bearing stainless steel based on charge transfer caused by the microdomain potential difference
[J].
Collapsing the proton motive force to identify synergistic combinations against Staphylococcus aureus
[J].
A protonmotive force drives ATP synthesis in bacteria
[J].
Energetics of pathogenic bacteria and opportunities for drug development
[J].
An antibacterial mechanism of titanium alloy based on micro-area potential difference induced reactive oxygen species
[J].
Construction of a rough surface with submicron Ti2Cu particle on Ti-Cu alloy and its effect on the antibacterial properties and cell biocompatibility
[J].
Effect of phase conditions on tensile and antibacterial properties of Ti-Cu alloys with Ti2Cu intermetallic compound
[J].
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