恒电位—恒电流瞬态响应技术研究钝化膜多层结构

采用恒电位－恒电流（Ｐ－Ｇ）瞬态响应技术研究了２２０５和３１６Ｌ不锈钢在０．５和１．０ｍｏｌ／ＬＮａＣＩ溶液中钝化膜的结构和稳定性。研究结果证实，体系的钝化膜均具有多层结构。讨论了氯离子在钝化膜生长和破坏过程中的作用。并提出可能的作用模式和破坏机制。由Ｐ－Ｇ响应曲线计算得到的各特征参数随极化电位的变化关系表明。２２０５双相钢在ＮａＣＩ介质中的耐蚀性明显高于３１６Ｌ不锈钢。另外，初步探讨了２２０５钢     

恒电位－恒电流瞬态响应技术研究钝化膜多层结构──Ⅱ．2．5mol／LH_2SO_4溶液中2205和316L不锈钢钝化膜的结构与生长规律的研究

采用恒电位－恒电流（Ｐ－Ｇ）瞬态响应技术研究了２２０５和３１６Ｌ不锈钢在２．５ｍｏｌ／ＬＨ２ＳＯ４溶液中钝化膜的结构．研究结果证实这两种体系的钝化膜均具有多层结构．利用由Ｐ－Ｇ响应曲线计算得到的各特征参数随极化电位和极化时间的变化关系，有效地分析了两种体系钝化膜的稳定性及生长规律．     

复杂钝化体系P－G响应特征的研究

采用恒电位－恒电流（Ｐ—Ｇ）瞬志响应技术研究了多层结构钝化膜和存在吸附层钝化膜的复杂钝化体系提出了判断钝化膜多层结构的方法以及表征钝化膜不同层稳定性的特征参数，并建立了描述复杂钝化体系Ｐ—Ｇ响应特征的数学模型．研究了２２０５和３１６Ｌ不锈钢在２．５ｍｏｌ／ＬＨ２ＳＯ４中钝化膜的结构，以及吸附型缓蚀剂哌啶和癸胺对３０４不锈钢在０．５ｍｏｌ／ＬＮａＣｌ介质中孔蚀的抑制作用研究结果证实所建立的模型能很好地反映研究体系的Ｐ—Ｇ响应特征．利用提出的特征参数随极化电位和极化时间的变化关系，有效地分析了钝化膜的生长规律和稳定性，以及缓蚀剂对孔蚀发生与发展过程的抑制作用     

恒电位—恒电流瞬态响应技术研究钝化膜多层结构：Ⅱ.2.5mol／L H2SO4…

采用恒电位－恒电流瞬态响应技术研究了２２０５和３１６Ｌ不锈钢在２．５ｍｏｌ／ＬＨ２ＳＯ４溶液中钝化膜的结构，研究结果证实这两种体系的钝化膜均具有多层结构，利用由Ｐ－Ｇ响应曲线计算得到的各特征参数随极化电位和极化时间的变化关系，有效地分析了两种体系钝化膜的稳定性及生长规律。     

STUDY ON MULTIPLE-LAYER STRUCTURE OF PASSIVE FILM ON STAINLESS STEELS BY POTENTIOSTATIC-GALVANOSTATIC (P-G)TRANSIENT TECHNIQUE Ⅱ. Structure and Growth of Passive Film for 2205 and 316L Stainless Steels in 2.5 mol / L H_2SO_4

采用恒电位－恒电流（Ｐ－Ｇ）瞬态响应技术研究了２２０５和３１６Ｌ不锈钢在２．５ｍｏｌ／ＬＨ２ＳＯ４溶液中钝化膜的结构．研究结果证实这两种体系的钝化膜均具有多层结构．利用由Ｐ－Ｇ响应曲线计算得到的各特征参数随极化电位和极化时间的变化关系，有效地分析了两种体系钝化膜的稳定性及生长规律．     

恒电位－恒电流瞬态响应技术研究钝化膜多层结构──Ⅰ．多层结构钝化膜的P－G瞬态响应特征

采用恒电位－恒电流（Ｐ－Ｇ）瞬态响应技术研究了具有多层结构钝化膜的体系．分析了这类体系在钝化过程不同阶段的Ｐ－Ｇ瞬态响应特征．提出了判断钝化膜多层结构的方法以及表征钝化膜不同层稳定性的特征参数，并建立了描述复杂钝化体系Ｐ－Ｇ响应曲线的数学模型．研究结果证实所建立的模型能很好地反映体系的Ｐ－Ｇ响应特征．     

恒电位—恒电流瞬态响应技术研究钝化膜多层结构：Ⅰ.多层结构钝化膜…

采用恒电位－恒电流瞬态响应技术研究了具有多层结构钝化膜的体系，分析了这类体系在钝化过程不同阶段的Ｐ－Ｇ瞬态响应特征。提出了阉断钝化膜多层结构的方法以及表征钝化膜不同层稳定性的特征参数，并建立了描述复杂钝化体系Ｐ－Ｇ响应曲线的数学模型。研究结果证实所建立的模型能很好地反映体系的Ｐ－Ｇ响应特征。     

哌啶对Cr25铁素体不锈钢在中性NaCl介质中钝化膜破坏的缓…

采用稳态阳极极化曲线，电化学阻抗谱方法和恒电位－恒电流瞬态响应测试技术研究了有机缓蚀剂哌啶对Ｃｒ２５铁素体不锈钢在ＮａＣｌ介质中钝化膜破坏的抑制作用，以及缓蚀剂浓度和Ｃｌ＾－浓度对钝化膜稳定性的影响。     

STUDY ON MULTIPLE-LAYER STRUCTURE OF PASSIVE FILM ON STAINLESS STEEL BY POTENTIOSTATIC-GALVANOSTATIC (P-G) TRANSIENT TECHNIQUE Ⅰ. P-G Response Characteristics of Passive Film with Multiple-Layer Structure

采用恒电位－恒电流（Ｐ－Ｇ）瞬态响应技术研究了具有多层结构钝化膜的体系．分析了这类体系在钝化过程不同阶段的Ｐ－Ｇ瞬态响应特征．提出了判断钝化膜多层结构的方法以及表征钝化膜不同层稳定性的特征参数，并建立了描述复杂钝化体系Ｐ－Ｇ响应曲线的数学模型．研究结果证实所建立的模型能很好地反映体系的Ｐ－Ｇ响应特征．     

316L不锈钢微动磨蚀过程表面钝化膜自修复行为研究

采用球－平面接触设备,对轧制固溶３１６Ｌ不锈钢不不同ＮａＣｌ溶同动过程中,表面钝化膜的自修复行为进行了研究,讨论了溶液腐蚀特性及缝隙腐蚀行为对微动过程的影响,结果表明,溶液腐蚀特性的改变引起材料钝化膜自修复行为的差异,但不显著,在去离子水溶液中,３１６Ｌ不锈钢表面钝化膜保护了较高的自修复能力,稳定阶段表面钝化膜自修复约占平衡态下钝化膜厚度的１７％,说明３１６Ｌ不锈钢表面钝化膜在微动过程并能长期有效     

恒电位—恒电流瞬态技术研究钝化膜的稳定性

建立了研究钝态金属的恒电应—恒电流(P-G)瞬态响应的微计算机在线测量系统和存在孔蚀时的 P-G 响应曲线的数学模型,由采样得到的响应曲线数据,应用蒙特卡罗法算出表征钝化膜稳定性的电化学参数。用此技术研究了一些合金钢在氯化钠溶液中的钝化膜稳定性并讨论了钝化膜局部破坏的原因。     

Depassivation-repassivation behavior of type-312L stainless steel in NaCl solution investigated by the micro-indentation

Repassivation behavior of type-312L stainless steel containing 6% of molybdenum was examined in NaCl solution using in situ micro-indentation technique, together with type-304 and 316L stainless steels. High stability of the passive film formed on the type-312L stainless steel was also examined by depth profiling analysis of passive films using glow discharge optical emission spectroscopy (GDOES). In 0.9 mol dm⁻³ NaCl solution at 296 K the type-304 and 316L stainless steels are passive only up to 0.3 V (SHE), above which pitting corrosion occurs. In contrast, no pitting corrosion occurs on type-312L stainless steel. Despite the significant difference of the pitting corrosion resistance, the repassivation kinetics of the three stainless steels, examined by micro-indentation at 0.3 V (SHE), is similar. The presence of molybdenum in the stainless steel does not influence the repassivation kinetics. The charge required to repassivate the ruptured type-312L stainless steel surface increases approximately linearly with the potential, even though the passivity-maintaining current increased markedly at potentials close to the transpassive region. Repassivation occurs without accompanying significant dissolution of steel, regardless of the stability of passive state. Depth profiling analyses of the passive films on the type-312L stainless steels formed at several potentials revealed that molybdenum species enrich in the outer layer of the passive film, below which chromium-enriched layer is present. The permeation of chloride ions may be impeded by the outer layer containing molybdate, enhancing the resistance against the localized corrosion of the type-312L stainless steel.     

2205双相不锈钢与316L奥氏体不锈钢钝化膜内点缺陷扩散系数的计算分析

应用电容测试法并借助于点缺陷模型（PDM）计算了2205双相不锈钢与316L 奥氏体不锈钢在NaCl溶液中所形成的钝化膜内点缺陷的扩散系数,利用实验测得钝化膜的稳态电流和PDM模型对计算结果进行了验证分析。通过两种计算方法得到点缺陷在2205双相不锈钢与316L奥氏体不锈钢钝化膜内的扩散系数约为10^-23cm²/s~10^-20 cm²/s数量级,并发现在模拟海水溶液中2205钢的扩散系数比316L钢小,氧空位所形成的点缺陷在2205钢的钝化膜内比316L钢扩散困难,从而使得2205不锈钢的钝化膜比316L不锈钢更加致密与完整,保护性能更好。     

2205和316L不锈钢在氢氟酸中的电化学腐蚀行为

通过动电位极化和电化学阻抗方法考察了2205双相不锈钢和316L不锈钢在5%(体积分数)HF溶液中的电化学行为,借助Mott-Schokkty曲线分析了两种不锈钢表面钝化膜的半导体特性。结果表明：两种不锈钢在氢氟酸溶液中都能发生钝化,且2205双相不锈钢的钝化区间范围更宽,维钝电流密度更低。2205双相不锈钢表面钝化膜表现出更高的钝化膜电阻和电荷转移电阻,其抗氢氟酸腐蚀性能优于316L不锈钢,这主要与2205双相不锈钢中的Mo和Cr含量高、表面钝化膜缺陷少、钝化膜易修复等因素有关。     

Corrosion resistances and passivation of powder metallurgical and conventionally cast 316L and 2205 stainless steels

The corrosion resistances and passivation of austenitic 316L and duplex 2205 powder metallurgical (P/M) steels, produced by gas atomizing and hot isostatic pressing (HIP), have been compared with those of their conventional cast counterparts. P/M 316L steel is shown to have significantly higher pitting corrosion resistance than conventional 316L steel in 0.5 M HCl. This effect is ascribed to the fine grained microstructure of the P/M 316L steel yielding an improved passive layer. The latter hypothesis is supported by photoelectron spectroscopy data demonstrating differences between the thickness and composition of the passive layers for the 316L steels.     

The corrosion behaviour of austenitic and duplex stainless steels in artificial saliva with the addition of fluoride

The evolution of the passive films on 2205 duplex stainless steel (2205 DSS) and AISI 316L stainless steel in artificial saliva, and with the addition of fluoride, was studied using electrochemical impedance spectroscopy (EIS) and potentiodynamic measurements. The extent of the passive range increased for the 2205 DSS compared to the AISI 316L in both solutions. The formation of the passive film was studied by EIS at the open-circuit potential (OCP). The passive layers were studied at the OCP by X-ray photoelectron spectroscopy (XPS). The passive films on both materials predominantly contained Cr-oxides, whereas the Fe species were markedly depleted.     

光电化学方法研究不锈钢钝化膜的局部破坏

建立了评价钝化膜稳定性的光电化学方法——电位台阶光电流测量和恒电位光电流响应测量。研究了铁素体高铬不锈钢25Cr和奥氏体不锈钢AISl304,316L,321在0.1mol/LNaCI溶液中钝化膜的局部破坏及十二烷基苯磺酸钠和癸胺对AISI304不锈钢孔蚀的抑制作用。结果表明:钝化膜破坏后光电流增加;电位台阶光电流测量得出光电流开始突增的电位值与钝化膜的击穿电位对应,钝化膜破坏后光电流i_(ph)随电极电位增加值△E_b的变化规律可以反映钝化膜破坏的本质;缓蚀剂的加入改变了AISI304不锈钢i_(ph)