H2S环境中UNS J91540不锈钢的电化学行为对SCC的影响

应用慢应变速率拉伸试验和电化学方法研究了湿硫化氢溶液中UNS J91450不锈钢的电化学行为对应力腐蚀开裂的影响.结果表明,本实验条件下UNS J91540不锈钢具有较高的SCC敏感性,并随着溶液pH的降低而明显增大.该不锈钢的电化学行为对它的腐蚀开裂(SCC)敏感性具有重要影响.开路电位下该不锈钢的SCC行为同时受氢脆作用和裂纹尖端阳极溶解作用的影响.在pH较低的介质中析氢电流较高而裂纹尖端阳极溶解作用略低,而在pH较高的介质中析氢电流较低而裂纹尖端的阳极溶解作用相对增强.氢脆作用对UNS J91540不锈钢SCC敏感性影响更显著.     

双相不锈钢的选择性腐蚀研究(英文)

双相不锈钢中的铁素体(α相)和奥氏体(γ相)具有不同的晶体结构和化学成分,使之在水溶液环境中表现不同的耐蚀特征.本文应用空间分辨电化学技术测量2205双相不锈钢中铁素体和奥氏体的电位差异,并用电镜技术分析了α相和γ相的选择性腐蚀形态.结果表明,在0.01mol/LNaCl溶液中,铁素体的腐蚀电位比奥氏体高,而在2mol/LH2SO4+xmol/LHCl溶液中,双相不锈钢在活化＿钝化电位区出现两个明显的阳极电流峰.铁素体相的选择性腐蚀发生在较负的阳极峰电位,而奥氏体则在较正的阳极电位峰发生选择性腐蚀.     

亚稳态304不锈钢应力腐蚀影响因素探讨

30 4不锈钢通过低温拉伸制得含有不同马氏体相变量的试样 ,由于冷加工将不可避免地导致位错密度大幅度增加 ,利用铁素体测量仪和透射电镜 (TEM )检测并分析 30 4不锈钢位错形态 .上述试样在 4 2 %MgCl2 沸腾溶液中用慢应变速率法 (SSRT) ,结合金相显微镜 ,扫描电子显微镜等表面分析手段 ,探讨了微观组织变化对 30 4不锈钢应力腐蚀的影响 .结果表明 :由于马氏体相和位错缺陷的交互作用 ,影响了 30 4不锈钢在沸腾MgCl2 溶液中应力腐蚀敏感性 ,且在不同变形量范围内 ,影响的主导因素不同     

双相不锈钢在水溶液中之腐蚀疲劳与动态应变时效

本研究主要探讨 2 2 %Cr双相不锈钢在含氯离子水溶液中之腐蚀疲劳裂缝成长行为 ,以及在慢应变速率拉伸试验过程中所发生的动态应变时效现象 .同时以 31 6L沃斯田体系不锈钢及4 30肥粒体系不锈钢作为比较 ,藉以探讨不同晶体结构对腐蚀疲劳及动态应变时效行为的影响 .实验结果显示 ,在 80℃ ,3.5wt%NaCl水溶液中 ,3种不锈钢并未发生应力腐蚀破裂 ,但其中 31 6L沃斯田体系不锈钢及 2 2 %Cr双相不锈钢却发生动态应变时效 ,且动态应变时效的发生与温度 ,应变速率及沃斯田体相的组织有关 .在NaCl水溶液中 ,采用预裂试片量测疲劳裂缝生长速率 ,其结果表明 ,4 30肥粒体系不锈钢之疲劳裂缝生长速率最快 ,而氢脆是加快裂缝生长速率的主因 ,就双相不锈钢而言 ,腐蚀疲劳裂缝的生长主要与该不锈钢所含之肥粒体相的氢脆现象有关     

应变速率和电位对应力腐蚀裂纹扩展的影响

以滑移-溶解-再钝化模型为基础,推导出应力腐蚀裂纹扩展速率与裂尖应变速率和电位之间的理论公式.计算表明,在裂纹扩展速率与裂尖应变速率的关系曲线中有两个特征区域.裂纹扩展速率在区域I随裂尖应变速率增加而增大,而在区域II不随裂尖应变速率的改变而变化.用慢应变速率拉伸技术（SSRT）测量了304L不锈钢的裂纹增长速率.当电位控制在区域II的阳极区时,理论计算的裂纹扩展速率与实验得到的结果比较吻合.     

海洋微生物对316不锈钢的电化学腐蚀行为

采用自腐蚀电位、电化学极化曲线、电化学阻抗谱技术研究了316不锈钢在无菌培养基介质和海水微生物接种培养有菌培养基介质中不同周期的腐蚀行为．结果表明,316不锈钢电极在有菌介质中比在无菌介质中的腐蚀电流密度大,腐蚀电位负移,微生物加速了不锈钢的腐蚀速度．随着浸泡时间的增加,有菌介质中的不锈钢电极极化电阻值逐渐减小,表明了海洋微生物的附着和繁殖加速了316不锈钢的腐蚀速率,降低了其在海洋环境中的耐蚀性．     

18／8型不锈钢在受力形变条件下腐蚀电化学行为的研究

应用电化学稳态技术、电化交流阻、抗微区电化学技术及扫描电等方法，研究１８／８型不锈钢在Ｎａ２Ｓ２Ｏ３稀溶液中，受外力形变条件下，的腐蚀电化学行为，结果表明，力学因素可使表面腐蚀电化学活性增加，表面微裂纹的发生、消失和再钝化的动态过程，同时受电位和拉应力的影响；点腐蚀可优先发生在应力集中位置，点蚀的发展可能诱导不锈钢的应力腐蚀开裂。     

硫化锰夹杂溶解和微生物存在对不锈钢管发生点蚀

结合发电厂凝汽器不锈钢管内壁腐蚀部位分布规律和腐蚀外貌特征,分别对腐蚀部位沉积物、内壁蚀孔附近管材成分进行扫描电子显微镜观察和能谱分析,探讨了管材中MnS溶解与微生物对凝汽器不锈钢管腐蚀的电化学反应机理,发现二者在点蚀形成过程中具有协同作用,并在综合分析影响不锈钢腐蚀的各种因素的基础上,提出了不锈钢凝汽器在运行过程中应采取的防护措施。     

新型十二烷基三甲氧基硅烷/氧化石墨烯复合膜对430不锈钢耐蚀性能的影响

使用一步电沉积法在430不锈钢上制备出十二烷基三甲氧基硅烷(DTES)/氧化石墨烯(GO)复合膜。 拉曼光谱(Raman)与扫描电子显微镜(SEM)测试表明,氧化石墨烯均匀地混合在硅烷膜中,并用电化学交流阻抗与极化曲线方法对这种复合膜所保护的430不锈钢进行耐蚀性能测试。 结果显示,在3.5%NaCl溶液中,430不锈钢会发生腐蚀反应,而存在硅烷复合膜的430不锈钢的耐蚀性能显著地提高。 研究表明,由于氧化石墨烯出色的阻隔性能一定程度上弥补了硅烷膜的缺陷,而且延长了腐蚀介质通过硅烷基质的路径,因此复合膜有着对基底物质更强的保护性能。     

敏化处理304不锈钢局部腐蚀行为的扫描微电极法研究

通过扫描微电极法研究敏化处理奥氏体不锈钢(304ss)的局部腐蚀行为,并结合传统电化学方法及光学显微镜进行测试观察. 结果表明,在10% FeCl3溶液未敏化处理(304ss-NS)或550 oC轻度敏化处理(304ss-S1)的不锈钢倾向于发生点腐蚀,而650 oC(304ss-S2)或750 oC(304ss-S3)深度敏化处理不锈钢则倾向于发生晶间腐蚀.     

Characterization of the Passive Film and Corrosion of Martensitic AM355 Stainless Steel

Electrochemistry methods were used to investigate the influence of pH on the passive film and corrosion behavior of ultrahigh strength AM355 stainless steel in chloride-containing media. Analysis of the Pourbaix diagram indicates that AM355 stainless steel exhibits higher corrosion resistance in natural and near-natural environments than that in acidic and alkaline conditions. Electrochemistry measurements and composition analysis of the passive film show that pitting potential increased due to the enhanced repassivation capacity of AM355 stainless steel with increasing pH. The mixed MnS/oxide inclusions are the main pitting sensitive locations under all conditions. Morphological observations and energy-dispersive spectroscopy showed that the influence of the gap between the martensitic laths is significant with increasing pH. The inclusions, element concentrations, and microstructures weaken the resistance of ultrahigh-strength martensitic AM355 stainless steel against corrosion.     

苯并三氮唑对18-8钢应力腐蚀开裂的缓蚀作用

利用慢应变速率技术（SSRT），并结合电化学极化曲线和阻抗实验方法研究了苯并三氮唑（BTA）添加剂对1Cr18Ni9Ti奥氏体不锈钢在0．5mol·L－1HCl＋0．5mol·L－1NaCl溶液中应力腐蚀和均匀腐蚀的缓蚀作用．结果表明，这种添加剂的缓蚀作用主要是抑制腐蚀的阳极过程而产生的．     

Investigation of Glass-Like Sol-Gel Coatings for Corrosion Protection of Stainless Steel Against Liquid and Gaseous Attack

Glass-like sol-gel coatings have been investigated as corrosion protective coatings on stainless steel. Magnesium- and borosilicate coatings with thickness of about 100–700 nm and methyl-modified SiO2 coatings with a thickness of about 2 m were deposited on stainless steel plates by dip-coating. The coatings were densified between 400°C and 500°C in different atmospheres (N2, air) for 1 h. The corrosion protection against gaseous attack was investigated by accelerated corrosion tests, at 800°C in air for 1 h. A corrosion protection factor was calculated from the relation Fe/Fe2O3, determined by XRD on the surface of coated and uncoated samples. Methyl-modified SiO2 coatings showed a protection factor, which was 2 orders of magnitude higher than for the other coatings. Electrochemical investigations were performed on samples submerged in a NaCl solution for 200 h. The corrosion propagation, polarization resistance and impedance vector were measured. For accelerated corrosion tests, polarization intensity curves were determined for high potentials of up to 1 V. Again excellent results were obtained for the methyl-modified SiO2 coatings, which remained passive for 200 h. Results of the salt spray corrosion test, however, showed no corrosion protection by the sol-gel coatings. After 2000 h in the salt spray chamber the steel was corroded and the coatings peeled off. It is concluded that for the further development of these coatings an improved interfacial passivation will be required.     

An Electrochemical Study on the Corrosion Inhibition of Stainless Steel by Polyaniline Film

Polyaniline(PANI)film was electrosynthesized on 304 stainless steel by cyclic voltammetry using aqueous oxalic acid as supporting electrolyte.The potential sweep rates were changed to achieve the PANI film with different thickness and structures.Protective properties of the PANI film for corrosion of stainless steel in 3% NaC1 aqueous solution were investigated by monitoring potentiodynamic polarization curves and electrochemical impedance spectroscopy(EIS).The results showed that the PANI film which was formed with lower sweep rate led to more positive shift of corrosion potential and greater charge transfer resistance,reflecting higher inhibition for corrosion of the stainless steel.     

Ormocer (ZrO2-PMMA) Films for Stainless Steel Corrosion Protection

The chemical protection of 316 L stainless steel coated with ORMOCER coatings of polymethylmethacrylate (PMMA) and ZrO₂ has been verified. The coatings were dip-coated on the substrates from sols prepared by mixing zirconium propoxide (ZrOC₃H₇)₄, isopropanol (C₃H₇OH), glacial acetic acid (CH₃COOH), polymethylmethacrylate and water under application of ultrasounds. The films were heat treated between 40 and 300°C in air up to 20 h. Their morphology was studied by electron scanning microscopy (SEM). Their anticorrosion behavior was analysed in 0.5M-H₂SO₄ solutions through potentiodynamic polarization curves at room temperature.The influence of the sol preparation, coating composition as well as of the duration and temperature of heat treatments on the corrosion parameters is reported. The films act as geometric blocking layers against the corrosive media and increase the lifetime of the substrate up to a factor 30.     

基于电化学噪声研究模拟海洋大气环境下304不锈钢的点蚀行为

基于电化学噪声技术建立了不锈钢海洋大气点蚀监测系统,利用该系统对处于干湿循环环境下不锈钢的点蚀行为进行监测. 使用时域谱图、时域统计、频域谱图和散粒噪声理论等分析方法对采集到的电化学噪声数据进行处理分析,并结合动电位极化法,形貌分析法共同研究不锈钢的点蚀行为. 研究结果表明,304不锈钢在模拟海洋大气环境下的点蚀行为分为钝化、亚稳态点蚀和稳态点蚀三个阶段. 在钝化阶段,电位电流噪声信号出现少量的同步异向波动,腐蚀事件发生频率高,平均电量低;在亚稳态点蚀阶段,电位电流噪声信号出现大量的同步同向波动,腐蚀事件发生频率降低,平均电量上升,通过扫描电镜观察蚀点;在稳态点蚀阶段,电位电流噪声信号不仅存在大量的同步同向波动,还出现了同步异向波动,腐蚀事件发生频率较低,平均电量大幅度上升,通过扫描电镜观察到电极表面出现小而浅的蚀点. 而动电位极化法可以证实304不锈钢点蚀的发生. 两种分析方法所得结果具有较好的一致性,证明该监测系统很好地实现了对模拟海洋大气环境下304不锈钢点蚀行为的连续监测,并能判断点蚀的发生.     

模拟地热水中304不锈钢管和镀锌钢管的腐蚀与结垢

采用扫描电子显微镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)和电化学测试的方法研究了304不锈钢管和镀锌钢管在模拟地热水(我国中部平原地热水的环境条件)中的腐蚀与结垢行为.结果表明,不锈钢管的结垢产物为"针"状物,其组成主要为CaCO3和MgCO3;镀锌钢管的腐蚀与结垢产物为"球"状物和"针"状物,其组成主要为Zn(OH)2、ZnO和CaCO3;腐蚀产物与结垢产物在晶核的形成生长过程中往往存在相互作用,同时它们在基材表面的分布对镀锌钢管的进一步腐蚀产生一定的抑制作用.     

丙炔醇对奥氏体不锈钢应力腐蚀的缓蚀作用

丙炔醇对奥氏体不锈钢应力腐蚀的缓蚀作用牛林＊林海潮曹楚南宋光铃（中国科学院金属腐蚀与防护研究所，金属腐蚀与防护国家重点实验室沈阳１１００１５）关键词丙炔醇，奥氏体不锈钢，应力腐蚀，缓蚀作用１９９７－０５－１３收稿，１９９７－０９－０２修回国家自然科学...     

添加钇提高不锈钢耐蚀性能的AES研究

用俄歇能谱仪对比研究了添加０．２％Ｙ对高硅不锈钢在９３％Ｈ２ＳＯ４介质中所形成的钝化膜中各元素浓度分布的影响，添加０．２％Ｙ增大了ＳｉＯ２在不锈钢钝化膜中的比例，从而使合金中Ｓｉ可充分形成富ＳｉＯ２的钝化膜。     

苯酚苯胺共聚物在304不锈钢电极表面的电化学合成及成膜微观结构分析

Electrochemical copolymerization of phenol and aniline was achieved on 304 stainless steel anodes in neutral water solution with an electrolyte of Na₂SO₄O₄. Compared with pit corro-sion potential of different copolymer coatings, the best solution composition was 0.09 mol/L phenol and 0.01 mol/L aniline. Through infrared spectrum analysis, polyaniline structure was proved in phenol-aniline copolymer, as well as more side chains. Scanning electron mi-croscope was used to analyze microstructure of copolymer coating, taking advantage of part solubility of phenol-aniline copolymer in tetrahydrofuran, the bifurcate network structure was observed. The copolymer coating microstructure was summarized, compared with the performance of polyphenol coatings, the reasons of corrosion resistance enhancement with the addition of aniline in electropolymerization reaction was assumed as well.