硫酸盐还原菌对碳钢腐蚀行为的研究

发布时间：2018-05-05 06:00

  本文选题：SRB + 微生物腐蚀　； 参考：《中国民航大学》2015年硕士论文

【摘要】：采用金相显微镜观察法、电化学测量法,探究硫酸盐还原菌(SRB)对X70钢,20#钢,L245钢分别在油水体系下和土壤模拟溶液中的腐蚀过程。以便研究SRB对输油管道的内、外腐蚀。金相实验结果表明:当SRB存在时,碳钢表面先失去了金属的光泽,且出现某物质附着在试样表面,使得表面变得粗糙不平,并且发生点蚀,有蚀坑出现。随着浸泡天数越多,点蚀蚀坑相互连接,点蚀现象较为明显。在同样的培养温度下,SRB对碳钢腐蚀的速度随着浓度的降低而减慢,腐蚀程度随着浓度的减低而减小。在相同的SRB浓度条件下,温度改变后SRB对碳钢的腐蚀程度会受到影响。电化学实验结果表明,在油水体系中,SRB可以加速三种材质钢的腐蚀,增加其腐蚀倾向性。在浸泡初期,SRB对三种管线钢的腐蚀程度最强;浸泡的天数延长后,腐蚀过程仍在继续,只是反应的速率减慢了。SRB存在时,三种钢的阳极过程受阻,阴极过程处于主要的地位,促进了阴极去极化作用,同时,生物膜的存在对腐蚀过程具有促进作用。在土壤模拟溶液的介质溶液中,X70钢在浸泡5d时,明显显示出最大的反应倾向性,腐蚀电流密度最大。浸泡天数的增多,由于腐蚀产物的增加,腐蚀产物膜脱落,加强了基体的腐蚀。相同的温度条件下,SRB的浓度减小,SRB对碳钢腐蚀的速率随之减小,腐蚀程度逐渐减小。而在SRB浓度相同的条件下,不同温度下,30℃时腐蚀程度最深。在土壤模拟溶液中,当增加Cl-的浓度时,SRB对X70钢的腐蚀速率先减小后增大,而当增加SO42-的浓度时,SRB对X70管线钢的腐蚀速率先变大后变小。
[Abstract]:By means of metallographic microscope and electrochemical measurement, the corrosion process of X70 steel 20 # steel L245 in oil-water system and in soil simulated solution was studied. In order to study the internal and external corrosion of SRB to oil pipeline. The metallographic results show that when SRB is present, the surface of carbon steel loses the metallic luster first, and some substance is attached to the surface of the sample, which makes the surface become rough, pitting and corrosion pits appear. With the more days of immersion, the pitting pits are connected to each other, and the pitting phenomenon is obvious. At the same culture temperature, the corrosion rate of carbon steel decreased with the decrease of the concentration of SRB, and the corrosion degree decreased with the decrease of the concentration. Under the same concentration of SRB, the corrosion degree of SRB to carbon steel will be affected by the change of temperature. The results of electrochemical experiments show that SRB can accelerate the corrosion of three kinds of steel and increase its corrosion tendency in oil-water system. In the early stage of soaking, the corrosion degree of SRB to the three kinds of pipeline steels was the strongest, and the corrosion process continued after the immersion days were prolonged, but the anodic process of the three steels was blocked and the cathodic process was in the main position when the reaction rate slowed down. At the same time, the existence of biofilm can promote the corrosion process. In the medium solution of soil simulated solution, the steel X70 obviously showed the maximum reaction tendency and corrosion current density when immersed in the medium solution for 5 days. With the increase of soaking days, the corrosion of the substrate is strengthened because of the increase of corrosion products and the exfoliation of corrosion product film. At the same temperature, the concentration of SRB decreases and the corrosion rate of carbon steel decreases, and the corrosion degree decreases gradually. However, under the same SRB concentration, the corrosion degree is the deepest at 30 鈩，

本文编号：1846500