流动海水冲刷下TA2纯钛管路钝化膜腐蚀特性研究  

Effect of Flowing Seawater on Corrosion Characteristics of Passivation Film on TA2 Pure-Ti Pipes

作　　者：彭文山 邢少华 钱峣 蔺存国 侯健 张大磊 PENG Wenshan;XING Shaohua;QIAN Yao;LIN Cunguo;HOU Jian;ZHANG Dalei(National Key Laboratory of Marine Corrosion and Protection,Luoyang Ship Material Research Institute,Qingdao 266237,China;Qingdao Jimo District Bureau of industry and information technology,Qingdao 266205,China;School of Materials Science and Engineering,China University of Petroleum(East China),Qingdao 266580,China)

机构地区：[1]中国船舶集团有限公司第七二五研究所、海洋腐蚀与防护全国重点实验室,青岛266237 [2]青岛市即墨区工业和信息化局,青岛266205 [3]中国石油大学(华东)材料科学与工程学院,青岛266580

出　　处：《中国腐蚀与防护学报》2024年第4期1038-1046,共9页Journal of Chinese Society For Corrosion and Protection

摘　　要：TA2纯钛是新一代船舶海水管路材料,在海水冲刷下管路钝化膜失效会导致管路耐久性下降。研究海水冲刷对不同表面处理TA2纯钛腐蚀行为的影响对于评估TA2纯钛腐蚀和防护具有重要意义。采用动电位极化、电化学阻抗和Mott-Schottky分析等电化学测试方法研究了两种表面处理TA2纯钛在流动海水中的耐冲刷腐蚀性能,并对腐蚀后的试样进行腐蚀形貌观察和腐蚀产物分析。结果表明,5 m/s以内,海水流速的变化对TA2纯钛表面钝化膜的耐蚀性影响较小。电位升高时,在流动海水中钛合金表面钝化膜出现短暂的溶解现象,但很快就会进行再钝化修复,对材料的耐蚀性并未产生明显影响。相比于表面钝化处理试样,抛光状态试样在流动海水冲刷下阴极极化存在极限扩散特征,这主要是由于钝化状态试样表面已经形成了钝化膜,其对氧的消耗少于尚未形成钝化膜的表面抛光试样。抛光试样由氧传质速度控制的去极化发展慢,出现不随电位变化的极限电流密度。两种表面处理后的TA2纯钛钝化膜在海水中均只呈现n型半导体特征,且极化测试后材料表面平整,未出现明显局部腐蚀。TA2 pure-Ti is a new generation of marine pipeline material,and the flowing seawater induced failure of its passivation film can deteriorate the durability of TA2 pure-Ti pipes.Hence the effect of flowing seawater on the corrosion behavior of TA2 pure-Ti being subjected to different surface treatments is of great significance for evaluating the service performance of TA2 pure-Ti pipes.Herein,the corrosion behavior of two surface treated TA2 pure-Ti rings in flowing seawater was comparatively studied in a home-made seawater pipeline integrated simulation set by means of measurements such as dynamic potential polarization,electrochemical impedance,and Mott Schottky analysis,as well as characterization of corrosion morphology and corrosion products.The results showed when the seawater flow rate below 5 m/s,the change in seawater flow rate had a relatively small impact on the corrosion resistance of the passive film on the surface of TA2 pure-Ti.When the potential rises,the passive film on the surface of TA2 showed a transient dissolution in flowing seawater,but it would soon be re-passivated,which did not have a significant impact on the corrosion resistance of the substrate material.Compared to the surface passivation treated ones,the polished TA2 exhibit limited diffusion characteristics of cathodic polarization in flowing seawater.This is mainly due to the presence of a passivation film on the surface of the passivated TA2,which consumes less oxygen than the surface polished ones that have not yet formed a passivation film.The depolarization of the polished TA2,which was controlled by oxygen mass transfer rate develops slowly,resulting in a limit current density that does not vary with the potential.The passivation films on the TA2,after being subjected to two surface treatments only exhibit n-type semiconductor characteristics in seawater,and after polarization testing,the material surface is flat without significant local corrosion.

关 键 词：TA2纯钛 海水管路 冲刷腐蚀 电化学 钝化膜 

分 类 号：TG172[金属学及工艺—金属表面处理]