316L不锈钢在西沙海洋大气环境下的腐蚀行为评估

采用循环阳极极化、电化学阻抗谱(EIS)和扫描Kelvin探针技术(SKP)评估了在西沙群岛苛刻海洋大气环境下,316L不锈钢经过不同时间暴露后的腐蚀行为。研究结果表明,暴露时间的长短对316L不锈钢的钝化行为没有显著影响。在极化曲线上均表现为阳极活化溶解特征,钝化膜失去保护作用,且暴露时间越长,不锈钢表面破损越多。同时随着暴露时间的延长,不锈钢表面微区的Kelvin电位整体分布下降,且趋向于不均匀分布,电位波动逐渐增大,这可能是由于钝化膜发生破裂进而发生点蚀以及腐蚀产物积累造成的。     

Corrosion resistance of 316L stainless steel in acetic acid by EIS and Mott-Schottky

The properties of the passivation film formed on 316L stainless steel were studied by Electrochemical Impedance Spectroscopy （EIS）, Mott-Schottky and Voltammetry measurements in high- temperature acetic acid. The results show that the passivation film formed on 316L stainless steel is stable in 60% acetic acid solution from 25 ℃ to 85 ℃. As temperature increased, the polarization resistance decreased but the interface capacitance increased. There was hardly any relation between temperature and the intrinsic property semiconductor. The passivation film represents the p-semiconductor property in the potential interval of -0.5-0.1 V; represents the n-semiconductor property in the potential interval of 0.1-0.9 V; and represents the p-semiconductor property in the potential interval of 0.9-1.1 V. The voltammetry measurements show that the structure of the passivation film is stable when the temperature is lower than 55 ℃ and that its stability decreased when this temperature is exceeded.     

模拟冷却水中几种缓蚀剂对不锈钢耐蚀性的影响

采用极化曲线、Mott-Schottky图和交流阻抗谱研究了不同缓蚀剂对316L不锈钢的缓蚀效果.极化曲线结果显示,模拟水中不锈钢的耐蚀性能随着温度的升高而不断降低,不锈钢的点蚀倾向增大.缓蚀剂可以提高不锈钢的点蚀电位,从Mott-Schottky图分析,缓蚀剂的加入降低了不锈钢表面钝化膜的载流子浓度.用于实验的6种缓蚀剂中,TB5和TB7显示出了较好的缓蚀性能.     

硝酸钝化时间对S32750超级双相不锈钢腐蚀行为的影响

为了进一步提高S32750超级双相不锈钢（S32750 SDSS）的抗腐蚀性能，采用质量分数为40.0%的硝酸对其进行钝化处理，通过电化学极化曲线、电化学阻抗谱、Mott⁃Schottky曲线以及浸泡等方法，考察了硝酸钝化不同时间后S32750超级双相不锈钢的耐蚀性，并观察了腐蚀前后试样表面的腐蚀表面形貌。结果表明，钝化时间对S32750超级双相不锈钢钝化膜耐蚀性有显著影响，当钝化时间小于120 min时，钝化时间越长，腐蚀速率越小，钝化膜耐蚀性越好。     

904L不锈钢在5g/L H_2SO_4溶液中的腐蚀行为

为了研究904L不锈钢在5 g/L H2SO4溶液中的腐蚀行为,采用动电位极化测试、电化学阻抗测试(EIS)和X射线光电子能谱(XPS)研究其腐蚀行为,并分析其钝化膜的组成.结果表明,904L不锈钢极化后会发生自钝化,钝化区间为-0.2~0.6 V,电荷传递电阻为4 801Ω/cm2,表明904L不锈钢具有较强的耐蚀性能.X射线光电子能谱(XPS)研究表明,钝化膜主要成分为Cr2O3、Cr OOH、Cr(OH)3等化合物.因而904L不锈钢在5 g/L H2SO4溶液中可以表现出良好的耐蚀性能.     

Pitting corrosion of 316L stainless steel under low stress below yield strength

Pitting corrosion of 316L stainless steel(316L SS)under various stress was studied by potentiodynamic polarization,electrochemical impedance spectroscopy(EIS)and Mott-Schottky(M-S)analysis in 3.5% NaCl solution.The results of polarization curves show that,with the increase of the stress,the pitting potentials and the passive current density markedly decrease firstly(180 MPa),and then increase greatly(200 MPa).The corresponding surface morphologies of the samples after the polarization test well correspond to the results.Mott-Schottky analysis proved the least Cl-adsorbed to the surface of passive film with more positive flat potential,indicating that a moderate stress could increase the pitting corrosion resistance of 316L SS in 3.5% NaCl solution.     

Study on pitting process of 316L stainless steel by means of staircase potential electrochemical impedance spectroscopy

Pitting corrosion of 316L stainless steel in NaCl solution was investigated by means of staircase potential electrochemical impedance spectroscopy(SPEIS).The investigation focused on the transition of stainless steel from the passive state to pitting corrosion.Based on the evolution of electrical parameters of the equivalent electrical circuit,it is suggested that the most probable mechanism of pit creation is the film breaking model.The result demonstrates that staircase potential electrochemical impedance...     

Constituent phases of the passive film formed on 2205 stainless steel by dynamic electrochemical impedance spectroscopy

The passive film formed on 2205 duplex stainless steel(DSS) in 0.5 M NaHCO3+0.5 M NaCl aqueous solution was characterized by electrochemical measurements,including potentiodynamic anodic polarization and dynamic electrochemical impedance spectroscopy(DEIS).The results demonstrate that there is a great difference between the passive film evolutions of ferrite and austenite.The impedance values of ferrite are higher than those of austenite.The impedance peaks of ferritic and austenitic phases correspond to th...     

氮含量和环境温度对316L不锈钢耐腐蚀性的影响

研究低温条件下腐蚀溶液温度以及钢中氮含量对316L奥氏体不锈钢耐腐蚀性能的影响,在1mol／L H2SO4＋0．5mol／L NaCl的腐蚀液中,对氮含量为0．0095％～0．5575％的316L奥氏体不锈钢进行阳极极化曲线及电化学阻抗测量。结果表明,提高氮含量,316L奥氏体不锈钢耐蚀性增强;腐蚀液温度升高,316L奥氏体不锈钢耐蚀性减弱。     

奥氏体不锈钢表面等离子渗锆合金层的抗酸腐蚀性研究

为提高0Cr18Ni9Ti奥氏体不锈钢在特殊应用环境的耐酸腐蚀性能,采用双辉等离子渗金属技术在不锈钢基体表面渗锆,对渗锆合金层的相结构进行检测分析,将奥氏体不锈钢基体试样和表面渗锆试样分别在0.5 mol/LH2SO4溶液、0.5mol/L HNO3溶液、0.5 mol/L HCl溶液进行电化学腐蚀对比试验。结果表明:在H2SO4溶液、HNO3溶液、HCl溶液中,不锈钢基材的相对腐蚀速度分别是渗锆合金层的2.18倍、9.73倍、24.43倍;不锈钢基体表面腐蚀较为严重,而渗锆合金层表面仅出现轻微的局部腐蚀坑。奥氏体不锈钢表面渗锆后,渗锆合金层中合金元素呈梯度分布,且腐蚀时在表面形成了一层致密的氧化锆钝化膜,因而其抗酸腐蚀性能相对基体大幅提升,在HCl溶液比在H2SO4溶液和HNO3溶液中耐蚀效果更明显。     

成膜电位对2205 双相不锈钢在NaCl溶液中电化学行为的影响

不锈钢耐蚀性与钝化膜形成条件密切相关。采用动电位极化法、电化学阻抗谱和Mott⁃Schottky方法,研究了成膜电位（相对于饱和甘汞电极（SCE）的电位）对2205双相不锈钢（2205DSS）钝化膜在质量分数为3.5%的 NaCl溶液中的电化学行为。结果表明,2205DSS在25 ℃下质量分数为3.5%的NaCl溶液中具有良好的耐蚀性能;在0.10 V和0.60 V的成膜电位下,钝化膜形成过程为先多孔后致密,而成膜电位为0.90 V时,钝化膜最后还额外经历了一个疏松多孔的形成过程;随着成膜电位的增加,钝化膜中施主密度与受主密度均增加,钝化膜生成速率增加,但也促进了侵蚀性阴离子吸附性的增加;钝化膜外层缺陷和多孔性随成膜电位的增加而增加,导致钝化膜厚度增加;钝化膜内层膜在0.60 V的成膜电位下致密性最好,随着成膜电位增加至0.90 V,内层氧化物变为多孔,钝化膜致密性退化,钝化膜破裂倾向最大。     

三种不锈钢在含Cl^—衣康酸介质中的腐蚀行为

研究了３种不锈钢在衣康酸／氯化钠水溶液中的腐蚀和电化学特性并探讨了介质组成和温度的影响。结果表明,在一定范围内,随衣康酸浓度,氯化钠浓度和温芳的提高,不锈钢的腐蚀速率、致钝电流密度和维钝电流密度也有所增大,不锈钢的点蚀电位与衣康酸介质中Ｃｌ＾－浓度的对数间存在线性关系;     

Passivation method of 317L stainless steel used in medicine

The electrochemical performance of 317L stainless steel used in medicine under different conditions of passivation(Different conternts of HNO3 solution,different passivation time and different passivation temperatures)was studied.The results show that the pitting potential of 317L stainless steel used in medicine can reach about 1.0V(SCE) when electrochemically tested in 0.9% NaCl solution after the steel was passivated in 30% HNO3 solution at 35℃for 6h,which indicates that the passivation film has a relatively strong resistance to corrosion,The results also show that the corrosion resistance of the passivation film on the surface of 317SS can be increased after suitable amount of K2Cr2O7 is added into NHO3 passivation solution.     

X80钢及其焊缝在鹰潭土壤模拟溶液中的循环伏安行为

用循环伏安法研究了X80钢及其焊缝在鹰潭土壤模拟溶液中,溶液/电极界面上的电化学腐蚀反应。通过改变扫描速率、阳极电位上限、离子浓度、通气状态研究了钢的阳极极化和阴极析氢反应之间的相互作用。结果表明,酸性环境中的X80钢电化学行为是不可逆的电荷转移过程,钢的表面不能形成一个稳定的氧化膜。溶液中的侵蚀性离子使阳极极化和阴极析氢反应程度增加。阳极极化产生的稳定沉淀层对析氢反应起催化作用。氧气的存在能使钢表面能生成稳定的氧化膜,这会降低对析氢反应的催化作用。溶液中的CO2能增加焊缝的SCC敏感性。     

柠檬酸环境友好钝化液配方研究

针对传统的不锈钢钝化液使用浓硝酸、浓硫酸、铬酸等强氧化剂存在较高的安全隐患,操作条件苛刻的问题,采用挂片在滚筒中旋转浸泡的方式进行钝化,研究不锈钢柠檬酸双氧水钝化工艺,探讨最佳工艺条件,并利用塔菲尔曲线测得其自腐蚀电流密度以表征其耐腐蚀性能．研究表明：钝化效果的影响因素显著性顺序为柠檬酸质量分数〉双氧水质量分数〉钝化温度〉钝化时间;柠檬酸环境友好钝化液的最佳配方为：柠檬酸质量分数10％,双氧水质量分数15％,稳定剂F质量分数15％,缓蚀剂E质量分数1％,温度40℃,钝化时间60min．柠檬酸双氧水钝化后测得不锈钢自腐蚀电流密度为5．210×10^-6μA／cm2,小于传统钝化后测得的不锈铜自腐蚀电流密度（6．098×10^-6μA／cm2）．新型的柠檬酸配方钝化效果比传统配方的钝化效果好,对环境的污染负荷小,为化工集装罐实际钝化应用提供了基础数据．     

Study on the passive film formed on 2205 stainless steel in acetic acid by AAS and XPS

The properties of the passive film formed on 2205 stainless steel in acetic acid at high temperature that contained chloride ions were studied by atomic absorption spectrometry (AAS), X-ray photoelectron spectroscopy (XPS), and electrochemical polariza-tion measurements.AAS results show that molybdenum is enriched on the surface as the passive film is dissolved.This enrichment decreases the corrosion resistance because it hinders chloride adsorption and Fe ion dissolution, and acts as a local pH buffer because it consumes protons.The dissolution ratio of Fe/Cr is approximately 10 during the active dissolution of the passive film.XPS results indicate that when the potential is in the passivation region, Cr comprises about 50% of the metal cations in the near-surface region of the passive film and is the main metal constituent in this region.When the polarization potential is much greater than the transpas-sivation potential, the Mo content accounts for approximately 45% of the metal cations in the near-surface region; Fe and Ni have no obvious influence on the formation, dissolution, or puncture of the passive film.     

316L不锈钢焊缝联合防护技术研究

利用阴极保护和涂层相结合的联合保护技术提高316L不锈钢焊缝的耐腐蚀性能.通过测量试样的阴极极化曲线,分析了涂层和阴极保护之间的相容性;通过测量带有涂层的焊缝附近的极化曲线,确定了其自腐蚀电位;通过测量焊件不同区域的交流阻抗Bode图,并利用相关计算方法得出各区域的最佳保护电位;最后,利用保护度计算公式对焊件三区联合保护效果进行比较分析.结果表明:环氧煤沥青涂层与阴极保护之间具有良好的相容性,带涂层的不锈钢焊缝在阴极最佳保护电位下,腐蚀速率大大降低.因此,联合保护能够使不锈钢焊缝区达到很高的保护度.     

高氮不锈钢在模拟PEM燃料电池环境中的电化学性能

以高氮不锈钢为研究对象,304不锈钢作对比,在模拟PEM燃料电池环境中测试二者的极化曲线和交流阻抗,运用相关软件分析曲线和数据。实验结果表明：高氮不锈钢的自腐蚀电流密度和维钝电流密度分别比304不锈钢低21.7%和24.5%,说明高氮不锈钢比304不锈钢有更好的耐腐蚀性;高氮不锈钢的电荷转移电阻比304不锈钢高2.43×103倍,而且高氮不锈钢的弥散指数(N= 0.899 4)比304不锈钢的弥散指数(N = 0.844 5)更接近1,这表明高氮不锈钢的钝化膜比304不锈钢的厚而且光滑。     

不锈钢载波钝化的研究和应用

不锈钢载波钝化的研究已有近20年的历史，研究人员对不锈钢载波钝化理论作了较为深入的研究，并在载波钝化理论的应用上进行了广泛探索．综述了载波钝化膜的生长、膜层的结构和性质的研究进展情况及应用前景．     

X80和X70管线钢在NaHCO3溶液中钝化膜的电化学性能

采用动电位极化、交流阻抗和电容测量等方法研究了X80和X70管线钢在0．5mol／L NaHCO3溶液中的活化-钝化行为及生成的钝化膜的电化学性能。极化曲线表明,X80和X70钢在-0．16～0．90V发生了钝化,X70钢的雏钝电流密度（ip）约为18．38μA／cm^2,而X80钢的维钝电流密度约为6．76μA／cm^2。交流阻抗表明,X80钢表面生成的钝化膜比X70钢的更加致密,均匀性更好,与原子力显微镜（AFM）的观察结果相吻合。电容测量表明,X80和X70钢在该溶液中表面生成的钝化膜在-0．20～0．80V为n型半导体,且X80钢比X70钢表面钝化膜的施主密度更低,空间电荷层更厚,耐蚀性更好。