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1.
探讨了电化学方法在Al基体上沉积聚苯胺膜的控制工艺,研究了聚苯胺膜的耐蚀性.结果表明,Al基体上沉积一层Ni后,可用电化学方法沉积聚苯胺膜.循环伏安法的扫描电位上限、恒电流法的电流密度、恒电位法的电位范围和电解质的酸度均影响苯胺的聚合速度和聚苯胺膜的物理性能.动电位极化曲线表明,在0.5 mol/LNaCl 溶液中,用各种电化学方法沉积聚苯胺膜的Al样品,其点腐蚀电位比无膜时有所升高.Al基体表面覆盖导电聚苯胺膜以后,其耐蚀性能得到提高.  相似文献   

2.
根据不锈钢钝化膜的生长过程和钼酸盐的电化学反应机理,调制了相应的交变电场,并获得钼酸盐修饰的不锈钢钝化膜;用XPS和电化学测试研究了钝化膜的组成和性能.结果表明:调制相应的交变电场可以获得所需的组成结构和性能的产物;膜层具有理想的组成结构和性能,其耐蚀性得到提高.  相似文献   

3.
聚苯胺修饰不锈钢电极的腐蚀行为   总被引:7,自引:2,他引:5  
研究了由聚苯胺修饰的不锈钢电极在酸性介质中的腐蚀行为。结果表明,不同的聚苯胺表面膜耐蚀能力有显著区别。只有均匀、致密的聚苯胺膜才有较好的耐蚀能力。  相似文献   

4.
纯铁上电聚合苯胺膜的研究   总被引:2,自引:1,他引:1  
用电化学方法在纯铁阳极上聚合了苯胺膜,并用多种电化学和表面分析技术检测了聚苯胺修饰铁(Fe/PA)的耐腐蚀性能.结果表明,聚苯胺膜对铁基金属有很好的保护作用。在强碱性到弱酸性的水溶液中,Fe/PA 的腐蚀电流密度比纯铁降低了三个数量级。其过钝化电位则明显正移.  相似文献   

5.
化学合成得到了还原态聚苯胺,用紫外可见光光谱和红外光谱对其结构进行了表征.以还原态聚苯胺为功能成分,环氧树酯为成膜物质,按一定配方涂覆于不锈钢表面,验证了还原态聚苯胺膜层对不锈钢的防腐性能.结果表明,还原态聚苯胺不导电,但有较好的防腐能力.  相似文献   

6.
304不锈钢在垃圾渗滤液中的腐蚀行为   总被引:1,自引:0,他引:1  
用电化学极化曲线和电化学阻抗法研究了304不锈钢在垃圾渗滤液中的腐蚀行为.结果表明,在垃圾渗滤液中,不锈钢的腐蚀电位在-0.30~-0.60 V范围内波动,浸泡888小时后,平均腐蚀电流密度为2.829μA/cm2;不锈钢在垃圾渗滤液中具有良好的抗腐蚀性能,主要是由其表面活性点钝化引起的,并非钝化膜的阻隔作用.  相似文献   

7.
聚苯胺/聚吡咯复合薄膜的制备及其抗腐蚀性能研究   总被引:2,自引:0,他引:2  
采用循环伏安法在不锈钢表面电聚合聚苯胺/聚吡咯复合薄膜.利用动电位极化曲线法和电化学阻抗法研究了聚苯胺/聚吡咯复合薄膜的耐蚀性及其影响因素.结果表明:在3.5%NaCl溶液中,不锈钢表面覆盖复合膜以后,其自腐蚀电位比无膜和纯聚苯胺膜时提高,耐蚀性能增强,且复合膜的耐蚀性受电解液浓度、扫描次数、扫描速率及扫描上限等因素的影响.电解液中苯胺和吡咯的浓度比及硫酸浓度的高低,都会影响膜的致密度,从而影响膜的耐腐蚀性.电化学参数的改变会影响复合膜的聚合速率,使得复合膜的抗腐蚀能力不同.当苯胺和吡咯浓度比为7:3时,硫酸浓度为1.1 mol/L,扫描次数为25次,扫描速率为60 mV/s,扫描上限为1.2 V时,采用循环伏安法共聚合苯胺和吡咯,可形成沉积致密度高、耐蚀性好的复合膜.  相似文献   

8.
铁基金属表面苯胺及其衍生物电化学修饰膜的缓蚀作用   总被引:1,自引:1,他引:0  
研究结果表明,苯胺及其衍生物的电化学修饰膜对铁基金属有很好的保护作用,在氯化钠溶液以及弱酸性和强碱性溶液中有良好的阻蚀性能。18-8不锈钢经修饰后在3%NaCl溶液中的耐孔蚀性能大为提高,在硫酸溶液中的钝化特性明显改善。根据实验结果,探讨了修饰膜的缓蚀机理以及修饰物质的结构、取代基的位置对修饰膜耐蚀性的影响。  相似文献   

9.
采用原位氧化聚合法合成了不同质量比的纳米SnO2/聚苯胺复合材料,运用扫描电镜(SEM)、原子力显微镜(AFM)和X射线衍射(XRD)对材料进行表征,并在304不锈钢表面制备了纳米SnO2/聚苯胺的环氧涂层,利用电化学工作站和浸泡增重试验研究其耐蚀性能。结果表明,纳米SnO2/聚苯胺复合材料的防腐蚀效果优于聚苯胺,且当SnO2在复合材料中的质量分数为4%时,防腐蚀性能最佳。依据不锈钢表面复合涂层的结构,建立合理的等效电路,结合电化学阻抗谱数据,研究了纳米SnO2/聚苯胺/环氧复合涂层耐蚀性增强的机制。  相似文献   

10.
用循环伏安法在镁合金表面制备了聚苯胺膜层,并用扫描电子显微镜(SEM)和电极电位研究了聚苯胺膜的表面形貌和腐蚀防护性能.研究表明:聚苯胺膜层并不是均匀覆盖在基体表面,而且膜层表面存在很多的微孔;聚苯胺改变了膜层的电极电位;在腐蚀介质中聚苯胺膜以点蚀或剥离的方式进行腐蚀.  相似文献   

11.
目的选择合适的稀土制备Ti/Cr-RE双层涂层,提高不锈钢的耐腐蚀性能。方法采用两步粉末包埋法,先在304不锈钢表面渗Ti,再制备稀土改性Cr涂层,获得Ti/Cr-RE双层涂层。通过添加不同的稀土氧化物Y2O3和Ce O2,获得两种双层涂层,对比分析涂层的表面形貌、断面形貌及物相组成,利用电化学测试方法测定304不锈钢基体及两种Ti/Cr-RE双层涂层在3.5%(质量分数)Na Cl溶液中的电化学腐蚀性能。结果添加不同稀土元素钇、铈,都能在渗Ti不锈钢表面形成一层致密、连续的稀土改性渗铬层。在两种稀土元素改性的Cr涂层中,稀土元素分别与Cr,Fe,Ni,Ti形成了金属间化合物。304不锈钢基体的自腐蚀电位为-0.324 V,腐蚀电流密度为0.1363μA/cm2;钇改性铬涂层的自腐蚀电位为-0.341 V,腐蚀电流密度为0.2058μA/cm2;铈改性铬涂层则具有更高的自腐蚀电位(-0.263 V)及更低的腐蚀电流密度(0.030 86μA/cm2)。结论钇改性铬涂层不能提高304不锈钢基体的耐腐蚀性能,铈改性铬涂层可以明显提高基体的耐腐蚀性能。  相似文献   

12.
以Na_2CO_3为介质,利用电化学循环伏安法在不锈钢表面上电聚合沉积聚苯酚及聚邻苯二酚、聚邻氨基酚等聚合物膜,并采用阳极极化曲线法初步评估这些聚合物膜对不锈钢腐蚀的防护作用。试验所得聚合物膜呈棕色,均匀致密,与不锈钢基体的结合较好,在氯化钠溶液中的电化学测试表明,聚苯酚及其衍生物薄膜均能有效地提高不锈钢的耐腐蚀性。  相似文献   

13.
Coatings of zirconium oxide were deposited onto three types of stainless steel, AISI 316L, 2205, and tool steel AISI D2, using the ultrasonic spray pyrolysis method. The effect of the flux ratio on the process and its influence on the structure and morphology of the coatings were investigated. The coatings obtained, 600 nm thick, were characterized using x-ray diffraction, scanning electron microscopy, confocal microscopy, and atomic force microscopy. The resistance to corrosion of the coatings deposited over steel (not nitrided) and stainless steel nitrided (for 2 h at 823 K) in an ammonia atmosphere was evaluated. The zirconia coating enhances the stainless steel’s resistance to corrosion, with the greatest increase in corrosion resistance being observed for tool steel. When the deposition is performed on previously nitrided stainless steel, the morphology of the surface improves and the coating is more homogeneous, which leads to an improved corrosion resistance.  相似文献   

14.
用失重法和电化学法系统地研究了20钢基体、两种Ni基涂层(Ni60JH和Delelo50)以及对比材料lCrl8Ni9Ti不锈钢在液/固两相流(5%H2SO4 15%石英砂)中冲刷与腐蚀的交互作用.实验表明:(1)在冲刷速率为5—10m/s时,Ni60JH涂层的耐冲刷腐蚀性能比基体高8—15倍多,并优于1Crl8Ni9Ti不锈钢;DelelO50涂层的耐冲刷腐蚀性能比基体高3—5倍多.(2)随着冲刷速率的提高,4种材料的冲刷腐蚀交互作用失重率在冲刷腐蚀总失重率中所占比例显著增大,由低速时的45%增加到高速时的80%,从而使冲刷腐蚀交互作用失重率在冲刷腐蚀总失重率中占主导地位.(3)在纯腐蚀中,Ni60JH涂层和1Crl8Ni9Ti不锈钢以均匀腐蚀为主要特征,而DelelO50涂层和20钢以选择性腐蚀为主要特征.  相似文献   

15.
To improve the marine corrosion resistance of stainless steel coatings fabricated by high-velocity oxyfuel (HVOF) spraying with a gas shroud attachment, the molybdenum (Mo) content of stainless steel was increased to form coatings with a chemical composition of Fe balance-18mass%Cr-22mass%Ni-2∼8mass%Mo. These coatings were highly dense, with <0.1 vol.% in porosity, and less oxidized, with 0.5 mass% in oxygen content at most. The corrosion mechanism and resistance of the coatings were investigated by electrochemical measurement, chemical analysis, and statistical processing. The general corrosion resistance of the coatings in 0.5 mol/dm3 sulfuric acid was improved with increases in Mo content, and the corrosion rate could be decreased to 8.8 × 10−2 mg/cm2 per hour (∼1 mm/year) at 8 mass% Mo. The pitting corrosion resistance of the coatings in artificial seawater was improved with increases in Mo content and was superior to that of the 316L stainless steel coating. The crevice corrosion resistance of the coatings in artificial seawater was improved and the number of rust spots at 4 mass% Mo was decreased to 38% of that for the 316L coating. Accordingly, Mo is highly effective in improving the corrosion resistance of the stainless steel coatings by HVOF spraying.  相似文献   

16.
采用超音速火焰喷涂技术(HVOF)在高强钢表面制备了316L不锈钢涂层,利用扫描电镜、显微硬度仪、电化学测试系统等设备对涂层金相组织、硬度、结合性能和抗腐蚀性能等进行了测试,并分析了WC-CoCr中间层对316L不锈钢粉末涂层结合强度及涂层界面的影响。结果表明:超音速火焰喷涂316L不锈钢粉末颗粒在喷涂中变形充分,形成较致密的涂层,并具有超过400 HV0.1的显微硬度;涂层具有较高自腐蚀电位,耐蚀性优于高强钢;涂层结合强度随着涂层厚度的减小、基体硬度的增加而提高;WC-CoCr底层可改善涂层界面结合,从而改善316L不锈钢涂层的结合性能。  相似文献   

17.
In this study, TiN and TiAlN coatings were deposited on AISI 316 L stainless steel substrates by PVD techniques. The composition and crystalline structure of the as-deposited coatings were analyzed by energy dispersive X-ray analysis (EDX) and X-ray diffraction (XRD) methods, respectively. The corrosion resistance studies of TiN-coated and TiAlN-coated samples were carried out in 0.9 wt % NaCl and SBF solutions using the electrochemical potentiodynamic polarization method and the wear behavior was evaluated with the ball-on-disk wear method at a sliding speed rate of 0.3 m/s under 2.5 N load in a dry medium. It was found that both TiN and TiAlN coatings exhibited relatively good corrosion resistance, however, TiAlN coatings showed a better corrosion resistance than TiN coatings. The TiAlN coating contributes positively against corrosion and wear behavior by increasing the surface hardness and by decreasing the friction coefficient of AISI 316 L stainless steel, respectively.  相似文献   

18.
Poly(3‐octylthiophene) (P3OT) was synthesized by direct oxidation of the 3‐octylthiophene monomer using ferric chloride (FeCl3) as an oxidant. Using the drop‐casting technique, P3OT coatings were deposited onto 304 type stainless steel electrodes. For the purpose of determining the effect of thermal annealing on the corrosion protection of stainless steel with P3OT coatings, the coated electrodes were thermally annealed for 30 h at two different temperatures, 55 and 100 °C. The corrosion behavior of P3OT coated stainless steel was investigated in 0.5 M sulfuric acid (H2SO4) at room temperature using potentiodynamic polarization curves (PPC), linear polarization resistance (LPR), and electrochemical impedance spectroscopy (EIS). The results indicated that the thermally treated P3OT coatings improved the corrosion resistance of the stainless steel in 0.5 M H2SO4. The best corrosion protection was obtained by the P3OT coating annealed at 100 °C. In order to study the temperature effect on the morphology of the coatings before and after the corrosive environment and compare it with corrosion protection, atomic force microscopy (AFM) and scanning electronic microscopy (SEM) were used.  相似文献   

19.
《金属精饰学会汇刊》2013,91(3):164-168
Abstract

Ni2Si intermetallic coatings were deposited on a substrate of 420 stainless steel using a high velocity oxy-fuel (HVOF) process. The electrochemical corrosion behaviour of the coatings in 3.5% NaCl solution was investigated by means of Tafel polarisation tests and electrochemical impedance spectroscopy (EIS) measurements. Two coatings with different thicknesses, 55 and 115?μm, were investigated. The results showed that the corrosion rate of the thicker coating was lower than that of stainless steel by one order of magnitude. Local attack of the substrate was observed after the polarisation test of this coating, while the coating was still intact. The thinner coating and the stainless steel substrate showed similar corrosion rates. In this case, the substrate was severely attacked after the polarisation test. Two time constants were observed in the EIS spectra of both coatings which were related to charge transfer processes and pore resistance, respectively.  相似文献   

20.
用失重法和恒电位极化法研究了45^#碳钢、1Cr18Ni9Ti、304不锈钢和Ni-P合金镀层在含s介质中的腐蚀性.结果表明,低温条件下,S^2-浓度变化对4种材料阴极极化和阳极极化影响较小,1Cr18Ni9Ti和304不锈钢的极化曲线相似,为典型的阴、阳极控制的电化学腐蚀过程,自腐蚀电位和自腐蚀电流相近;Ni-P合金镀层出现了钝化区;45^#碳钢出现了阳极控制的扩散过程.温度升高,腐蚀速率增大,1Cr18Ni9Ti和304不锈钢的极化率变大,Ni-P合金镀层的钝化性能减弱,1Cr18Ni9Ti、304不锈钢和Ni-P合金镀层均是含S介质中的耐蚀材料.  相似文献   

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