硫酸盐还原菌在顶空体积变化条件下所致镍的微生物腐蚀研究  

Microbiologically Influenced Corrosion of Nickel Caused by Sulfate-reducing Bacteria under Different Levels of Headspace Volume

作　　者：田原 蒲亚男 孙天翔 侯苏 陈守刚[1] TIAN Yuan;PU Yanan;SUN Tianxiang;HOU Su;CHEN Shougang(School of Materials Science and Engineering,Ocean University of China,Shandong Qingdao 266100,China)

机构地区：[1]中国海洋大学材料科学与工程学院,山东青岛266100

出　　处：《表面技术》2024年第4期68-76,97,共10页Surface Technology

基　　金：国家自然科学基金项目(5197229);国防科技重点实验室基金项目(JS220406)。

摘　　要：目的通过改变厌氧瓶内顶空体积,研究硫酸盐还原菌(SRB)对金属镍的微生物腐蚀(MIC)机理,进而为镍基合金的腐蚀防护提供依据。方法通过生物学检测技术、表面分析技术和电化学技术,评估了金属镍的MIC行为。结果随着顶空体积的增大,更多的H2S以气体的形式析出到顶空,液相中硫化物浓度越低,SRB浮游和固着细胞数越高,点蚀坑越深,镍的腐蚀速率越高。在200mL的固定培养基体积下,顶空体积为90 mL和450 mL的镍试样失重分别是10 mL时的1.1倍和1.4倍,相应的点蚀坑深度分别增加了1.6倍、2.3倍。在孵育7 d后,顶空体积为450 mL时低频阻抗模值最低,同时获得最大的腐蚀电流密度,达到7.64×10^(-6) A·cm^(-2)。结论利用细胞外镍氧化释放的电子在SRB细胞质中进行硫酸盐还原在热力学上是有利的,SRB所导致的镍的腐蚀属于EET-MIC。Nickel(Ni),an important alloying element,has been widely added to alloys to improve their corrosion resistance,and strengthened Ni-based alloys are commonly used in industries such as oil,gas,and offshore engineering,but still face the microbiologically influenced corrosion(MIC).The volume ratio of headspace/broth can affect microbial activity,thereby affecting the metabolism of biofilm and the process of extracellular electron transfer(EET).The MIC mechanism of Ni induced by sulfate-reducing bacteria(SRB)with varied headspace volume was investigated to provide a basis for the corrosion protection of Ni-based alloys.The MIC behavior of Ni was evaluated by biological detection,surface analysis,and electrochemical analysis techniques.Different headspace volume of 10 mL,90 mL,and 450 mL was regulated with glass bottles and glass beads of different sizes with a fixed broth volume of 200 mL.The sessile cell count of Desulfovibrio vulgaris was 107 cells/cm^(2) after the 3 d pre-growth.The D.vulgaris sessile cell count on Ni coupons in the anaerobic bottles with 10 mL headspace volume was 1.28×107 cell/cm^(2). The sessile cells count on Ni coupons in the 90 mL and 450 mL headspace volume increased by 213% and 288%, respectively compared with the 10 mL headspace. The fluorescence microscopy (FM) images also showed a relatively robust biofilm covering the Ni coupon surface. The corrosion rate of Ni coupon was analyzed by weight loss data and the maximum pitting depth distribution statistics (with a confocal laser scanning microscope, CLSM). The weight loss of Ni coupons with a headspace volume of 90 mL (1.1 mg/cm^(2)) and 450 mL (1.4 mg/cm^(2)) was 1.1 times and 1.4 times that of Ni coupons with the 10 mL headspace (1.0 mg/cm^(2)), respectively. The maximum pit depth after the 7 d incubation was 2.7 μm with 10 mL headspace volume, and the corresponding pitting depth increased 1.6 times (4.2 μm) and 2.3 times (6.1 μm) for 90 mL and 450 mL headspace, respectively. With a fixed broth volume of 200 mL in all bottles, a la

关 键 词：镍 微生物膜 硫酸盐还原菌 顶空体积 微生物腐蚀 点蚀 

分 类 号：TG174[金属学及工艺—金属表面处理]