酸性介质环境中温度对Ti–Mo合金耐蚀性的影响  

The Influence of Temperature on Corrosion Resistance of Ti-Mo Alloy in Acidic Medium

作　　者：魏亚 付禹 潘志敏 王雪飞 余伟 何石磊[3] 苑清英[3] 骆鸿 李晓刚 WEI Ya;FU Yu;PAN Zhi-min;WANG Xue-fei;YU Wei;HE Shi-lei;YUAN Qing-ying;LUO Hong;LI Xiao-gang(Institute for Advanced Materials and Technology,University of Science and Technology Beijing,Beijing 100083,China;Institute of Engineering and Technology,University of Science and Technology Beijing,Beijing 100083,China;CNPC Baoji Petroleum Steel Pipe Co.,Ltd.,Shaanxi Baoji 721008,China)

机构地区：[1]北京科技大学新材料技术研究院,北京100083 [2]北京科技大学工程技术研究院,北京100083 [3]宝鸡石油钢管有限责任公司,陕西宝鸡721008

出　　处：《表面技术》2022年第9期168-177,187,共11页Surface Technology

基　　金：中国石油科技创新基金(2019D–5007–0308);国家重点研究开发项目(2016YFB0301204);中央高校基本科研业务基金(FRF–MP–20–51,FRF–BD–20–28A2)。

摘　　要：目的 研究Ti–Mo合金在不同温度的20%HCl溶液中的腐蚀行为和腐蚀规律,并探究其环境腐蚀机理。方法 采用X射线衍射仪、扫描电子显微镜、电化学工作站以及X射线光电子能谱等对Ti–Mo合金的微观组织结构和不同介质环境中的耐蚀性进行了探究。结果 溶液介质温度对Ti–Mo合金的腐蚀行为具有显著影响。当温度从20℃上升到70℃时,腐蚀电位从-548.9mV(vs.Ag/AgCl)降低到-593.3mV(vs.Ag/AgCl),且腐蚀电流密度在20℃时最低,为36.925μA/cm~2,维钝电流密度也随温度升高而增加。此外,温度升高不会改变氧化膜的成分,但会使膜内载流子密度升高,导致氧化膜的半导体特性发生n–p型转变。当溶液温度为20、30、50、70℃时,腐蚀速率分别为1.138 3、2.931 7、35.217、39.838 6 mm/a,且腐蚀速率随着温度升高而增加。结论 溶液温度升高会使Ti–Mo合金氧化膜内缺陷增多,氧化膜的稳定性和耐蚀性降低。在腐蚀过程中α相与β相会形成微原电池,α相作为阳极更容易发生优先腐蚀,这是由于β相中Mo元素含量较高所致。Titanium alloy pipeline is playing an increasingly important role in petrochemical industry. This paper mainly explores the corrosion behavior of Ti-Mo alloy in 20wt.% HCl solution with different temperature changes, aiming at revealing the corrosion mechanism of Ti-Mo alloy and providing certain reference value for the application of Ti-Mo alloy in petrochemical industry.The titanium alloy used in this experiment is produced by CNPC Baoji Petroleum Steel Pipe Co., Ltd. The main components(wt.%) are as follows: 2.99 Mo, 0.60 Zr, 0.044 Fe, 0.014 C, 0.005 1 N, and the balance is Ti. X-ray diffraction(XRD) and Quanta 250 scanning electron microscope(SEM) were used to observe the phase and morphology of Ti-Mo alloy. Electrochemical test adopts typical three-electrode system, with saturated silver chloride electrode as reference electrode, platinum electrode as counter electrode, titanium alloy sample as working electrode with the area of 1 cm~2. The electrochemical experiment temperature were 20, 30 50 and 70 ℃. The potential range of polarization curve was -0.8 V(vs. Ag/AgCl) to 2 V(vs. Ag/AgCl) and the scanning frequency of electrochemical impedance spectroscopy(EIS) was 10Hz to 105 Hz. The chemical composition of the oxide film was studied by 250Xi X-ray photoelectron spectroscopy.The oxide film was formed at 0.5 V(vs. Ref) for 7 200 s. Mott-Schottky was used to explore the properties of semiconductor films. The experimental frequency of Mott-Schottky was 1 000 Hz, the scanning potential was 2 to-1 V with the step size of 20 mV. 20wt.% HCl solution was selected as the static immersion test solution, and the temperature of the solution was kept at 20 ℃, 30 ℃, 50 ℃ and 70 ℃ respectively. After soaking for 15 days, ultrasonic cleaning with distilled water and alcohol, drying, weighing with a balance with accuracy of 0.1 mg, and observing the morphology after corrosion with 3D laser confocal and scanning electron microscope.The solution medium temperature produced a great influence on the corrosion behavior

关 键 词：Ti–Mo合金 温度 氧化膜 微原电池 

分 类 号：TG174[金属学及工艺—金属表面处理]