切削液的微生物劣化对碳钢耐腐蚀行为的影响  

Microbial Degradation of Cutting Fluid and Its Effect on Anticorrosion Behavior of Carbon Steel

作　　者：李庆宏 杨懿 吴泽奇 朱红玲 申媛媛 张丽 胡浩 董丽华 LI Qinghong;YANG Yi;WU Zeqi;ZHU Hongling;SHEN Yuanyuan;ZHANG Li;HU Hao;DONG Lihua(College of Ocean Science and Engineering,Shanghai Maritime University,Shanghai 201306,China;Logistics Engineering College,Shanghai Maritime University,Shanghai 201306,China;Shanghai Greenstec Environmental Protection Technology Co.,Ltd.,Shanghai 201306,China)

机构地区：[1]上海海事大学海洋科学与工程学院,上海201306 [2]上海海事大学物流工程学院,上海201306 [3]上海绿晟环保科技有限公司,上海201306

出　　处：《润滑与密封》2020年第10期14-21,共8页Lubrication Engineering

基　　金：国家重点研发计划项目(2016YFB0300702);上海海事大学研究生创新基金项目(2017ycx003);上海市军民融合发展专项(2019-jmrh1-kj45).

摘　　要：利用平板划线法对切削废液中的微生物进行提纯分离及鉴定,分离出一种假单胞菌属P.xiamenensis种的优势菌种,将菌种接种至切削液中进行微生物劣化,并研究在含菌切削液中45钢的腐蚀行为。实验结果显示:该菌种在切削液中的数量级在106 CFU/mL以上;该菌能优先降解切削液中含氮表面活性剂,增加乳化液液滴的粒径,从而增加切削液的浊度;45钢在含菌切削液中浸泡15天后,表面出现了一层稀松多孔的生物膜,将生物膜去除后发现基体发生了严重的点蚀现象。极化曲线结果显示,碳钢在含菌切削液中的腐蚀电流密度是空白对照样的2.2倍。电化学阻抗结果显示,浸泡时间增长电荷转移电阻逐渐下降,耐蚀性变差,第5天出现了生物膜,且生物膜的厚度不断增加,基体在生物膜下发生严重的点蚀。A dominant Pseudomonas sp.strain(P.xiamenensis)was isolated from a waste metal cutting fluid by streak plate method.The biodegradation of metal cutting fluid(MCF)and corrosion behavior of 45 carbon steel in MCF influenced by P.xiamenensis were studied.Results show that P.xiamenensis can easily colonize in MCF without biocide and maintain its biomass beyond 106 CFU/mL.Nitrogenous surfactants are preferentially degraded by bacteria leading to the increasing of oil-in-water emulsion droplet and turbidity of MCF.A porous biofilm occurrs on the surface 45 carbon steel after 15 days immersion in MCF,and serious pitting corrosion is found when the biofilm is removed.Polarization curve results indicate that the corrosion rate of 45 steel in the bio-contaminated MCF is 2.2 times than in controlled MCF.The electron transfer resistance of 45 carbon steel presents a gradual decreasing tendency in the MCF under the influence of P.xiamenensis,which results in weakening of anti-corrosion of the steel.The biofilm appeares on the steel surface when im-mersed for 5 days and the thickness of biofilm is thickened with the extension of immersion time.Severely pitting corrosion attacks the substrate under the biofilm.

关 键 词：45钢 金属切削液 微生物劣化 腐蚀 电化学阻抗谱 

分 类 号：TG174.421[金属学及工艺—金属表面处理]