核燃料包壳材料Zr—4合金的缝隙腐蚀

采用模拟闭塞电池及动电位扫描法研究堆外模拟辐照与未辐照的Ｚｒ－４合金在水中的缝隙腐蚀敏感性，结果表明，当电流通过闭塞区时，溶液ＰＨ值随时间下降，在闭塞区内ＣＴ的浓度随时间呈线性增大，而且经辐照的Ｚｒ－４合金闭塞区溶液的ＰＨ下降及Ｃｌ增浓均比未经辐照的显著，动电位扫描国法测Ｚｒ－４合金模拟闭塞区溶液听了阳极极化曲线和线性极化批民模拟闭塞电池法的结果基本一致，证实了经辐照的Ｚｒ－４合金的缝隙腐蚀敏感性     

在EXCO溶液中LY12铝合金腐蚀孔隙内的化学,电化学变化

用模拟闭塞电池研究了ＥＸＣＯ溶液中ＬＹ１２铝合金在模拟区内溶液的化学状态变化，即测定了溶液的ｐＨ值，Ｃｌ＾－浓度及金属阳离子含量随时间的变化。按照上述分析结果配制了不同阶段的模拟闭塞区溶液，用三角波动电位扫描法测定了ＬＹ１２铝合金及其晶间析出和晶界贫铜区在溶液中的点蚀敏感性。     

矿井单体液压支柱密封圈槽腐蚀事故分析

分析探讨了矿井用单体液压支柱密封圈槽发生腐蚀的原因。采用常规方法对所用材质进行成分分析及金相分析，运用扫描电镜、能谱分析及动电位扫描法，测定Ｃｌ＾－的含量，腐蚀坑形貌及材质的极化曲线。测定了不同条件下的电偶腐蚀电流，并研究了Ｃｌ＾－含量等因素对缝隙腐蚀的影响。     

用闭塞电池研究7075T6合金在EXCO溶液中的腐蚀行为

用模拟闭塞电池研究了７０７５Ｔ６合金在ＥＸＣＯ溶液中的腐蚀行为，结果表明，模拟闭塞电池法可用来研究铝合金铁局部腐蚀处理，要闭塞电池内外，铝合金铁腐蚀行为有很大差别。     

硼掺杂金刚石薄膜电极电化学特性的研究

本文用未经任何表面处理的硼掺杂金刚石薄膜为电极材料，采用循环伏安法和计时电流法检测含Ｋ３Ｆｅ（ＣＮ）６的ＫＣｌ和ＨＣｌ－ＫＣｌ溶液的响应电流，对电极的基本特性，如响应时间，稳定性等进行了研究；同坟也对溶液ｐＨ值变化与因而造成的响应电流变化进行了研究。从与玻碳电极比较的角度出发，分别在含汞的酸性ＫＣｌ－ＨＮＯ３和中性ＫＣｌ体系中，在一定电位下预富集铅，而后用阳极扫描法检测Ｐｂ－Ｈｇ的溶出峰电流，对金     

钢铁表面高温氧化皮对基体钢腐蚀的影响

用静态挂片法，分别研究了表面有、无氧化皮的Ｊ－５５钢试片在３％ＮａＣｌ溶液和含Ｃａ＾２＋、Ｍｇ＾２＋、ＳＯ４＾２－、ＨＣＯ３＾－的３％ＮａＣｌ溶液中的腐蚀。表面无氧化皮试片均呈全面腐蚀，而表面有氧化皮试片均呈局部腐蚀。氧化皮的电位比基体电位正、氧化皮本身的不连续性是引起局部腐蚀的主要原因。     

青铜合金成分与合金的阳极行为

铸造不同成分的铜锡合金，通过人为腐蚀，利用ＬＳＶ（电位扫描）、ＸＲＤ、ＳＥＭ等多种手段进行分析，结果表明：１）含Ｓｎ量为１０％左右的青铜器在酸性含Ｃｌ＾－环境中易产生晶间腐蚀生成粉状锈，而２０％￣４０％含Ｓｎ量的青铜合金无明显晶腐蚀现象出现；２）含Ｓｎ量高于１０％的合金，在ＮａＣｌ溶液中在低电位处出现欠电位阳极电流峰（ＵＰＣ），且形成Ｖ型ＣａＣｌ晶相的电极表面膜。在较正电位处，铜锡合金及纯铜出现主     

非晶态Ni—Si—B系合金在FeCl3溶液中的腐蚀行为

用失重法研究了几种Ｎｉ－Ｓｉ－Ｂ系合金在ＦｅＣｌ３溶液中腐蚀行为，分别考查了腐蚀速率与材料组分，表面状态，溶液温度，浓度及ｐＨ值的关系。结果表明：随着Ｎｉ含量增加，表面状态越粗糙，溶液浓度增加，温度升高，ＰＨ值降低，均将使腐蚀速率增加。     

钛合金的电化学特性和腐蚀行为

ＳＳＴ－８６１钛合金在含有Ｃｌ＾－Ｈ２ＳＯ４溶液中的电化学特性和腐蚀行为表明，Ｃｌ＾－１对钛合金一定的活性作用，使钛合金溶解电位降低，Ｃｌ＾－浓度越大，其活化作用越强，腐蚀速度工大，稳定的钝化膜和ＭｎＯ２层对钛合金角保护作用，使腐蚀速度小，Ｃｌ＾－对其特性的影响也较小。     

CO2饱和高温弱酸性介质中Ni-Cu-P合金、纯Ni和A3钢的电化学行为

用线性极化法,极化曲线法和失重法研究了化学镀Ｎｉ－Ｃｕ－Ｐ非晶态合金,纯Ｎｉ和Ａ３钢于１４０℃,ｐＨ值５．０、ＣＯ２饱和的２Ｗ（ｗｔ）ＮａＳＯ４溶液中的腐蚀电化学行为,结果表明,在该介质条件下,Ｎｉ－Ｃｕ－Ｐ合金、纯Ｎｉ和Ａ３钢的耐蚀性依次减弱,比值为８１．２：２３．９：１．０。Ｎｉ－Ｃｕ－Ｐ合金于２５０￣５５０ｍＶ（ｖｓ ＯＰ）区间发生钝化;纯Ｎｉ在５０￣１５０ｍＶ和高于４００ｍＶ（ｖｓＯＰ）区     

Q235钢在模拟海水溶液中的缝隙腐蚀行为

目前,丝束电极测量多侧重定性分析,鲜见对不同腐蚀阶段缝隙内Cl~-和H~+浓度分布的定量研究。采用丝束电极(WBE)联合交流阻抗谱(EIS)方法研究了Q235钢的缝隙腐蚀行为,并配合离子选择性电极传感器(ISE)对缝隙腐蚀不同阶段中的Cl~-浓度和H~+浓度变化进行定量分析。结果表明:在模拟海水环境(3.5%NaCl,pH值6.8~7.0,25℃)15 d缝隙腐蚀试验中,Q235钢的缝隙腐蚀行为在诱发期、扩大期及稳定发展期的H~+浓度与Cl-浓度表现出不同的分布规律,发现了Cl~-向缝内迁移与富集现象,量化了缝隙内离子变化的全过程。     

碳酸钠-碳酸氢钠溶液中X-42钢楔形缝隙内的电位和pH值

埋地管道的涂覆层因损伤而开裂起翘,是引发其点蚀穿孔和应力腐蚀断裂的主要原因之一.为此,在自行设计的模拟涂覆层开裂起翘楔形缝隙的装置上,分别测量了缝隙开口宽度为0.1,0.2,0.3 mm时管道钢X-42在0.5 mol/L Na2CO3 1 mol/L NaHCO3溶液中缝隙内的电极电位、溶液pH值分布,讨论了缝隙开口宽度对电极电位、溶液pH值分布的影响.结果表明,在自然腐蚀试验条件下,楔形缝隙内自缝口向缝尖电极电位呈负移态势,pH值呈下降态势;0.1 mm的缝隙开口宽度具有更大的闭塞性,产生更为明显的缝隙腐蚀敏感性;当缝隙开口大于0.2 mm时,100h内缝内金属未发生腐蚀.     

酸性溶液中Cl-含量和温度对PH13-8Mo腐蚀行为的影响

为了解决在深海油气钻采中出现的酸性环境中对钻采设备的腐蚀问题,结合海洋中油气田的实际环境,在pH值为3的Na2SO4+H2SO4溶液中,采用电化学极化曲线、循环极化曲线、电化学阻抗谱(EIS)结合静态浸泡实验,分别研究了Cl-质量分数(1%、3.5%和7%)和溶液温度(4、25、50和80℃)对马氏体沉淀硬化不锈钢PH13-8Mo电化学腐蚀行为的影响,并采用点缺陷PDM模型结合闭塞电池理论对其腐蚀机理进行了分析.结果表明,随着溶液中Cl-浓度的升高,PH13-8Mo极化曲线中二次钝化的特性消失.溶液中Cl-浓度和温度的升高均使得PH13-8Mo的点蚀电位降低、点蚀保护电位降低,抗点蚀能力下降,腐蚀电流密度增大,钝化电位区间缩短,电荷转移电阻呈指数关系下降,样品表面腐蚀形貌由点蚀发展为全面腐蚀.     

Effect of temperature, chloride ion and pH on the crevice corrosion behavior of SAF 2205 duplex stainless steel in chloride solutions

An investigation was conducted to examine the crevice corrosion behaviors for SAF 2205 duplex stainless steel in NaCl solutions by using potentiostatic critical crevice temperature measurement. Potentiodynamic polarization technique was comparably used to study the electrochemical behavior. The influence of temperature, chloride concentration and pH on the critical crevice temperature and electrochemical behavior in NaCl solutions was studied. The critical crevice temperature of SAF 2205 DSS in 4% NaCl solution was about 28 °C. The critical crevice temperature decreased linearly with an increase in log [Cl⁻]. A maximum critical crevice temperature was found in 4% NaCl solutions at pH 8.5. The influence of the duplex microstructure on attack development and morphology was analyzed by scanning electron microscope.     

Studies on the corrosion behavior of cerium-implanted zircaloy-4 with GAXRD

In order to study the influence of cerium ion implantation on the aqueous corrosion behavior of zircaloy-4, specimens were implanted by cerium ions with a fluence range from 1×10¹⁶ to 1×10¹⁷ ions/cm² at maximum 150°C, using MEVVA source at an extracted voltage of 40 kV. The valence and elements penetration distribution of the surface layer were analyzed by X-ray photoelectron spectroscopy (XPS) and auger electron spectroscopy (AES) respectively. Glancing angle X-ray diffraction (GAXRD) was employed to examine the phase transformation due to the cerium ion implantation in the oxide films. Three-sweep potentiodynamic polarization measurement was employed to value the aqueous corrosion resistance of zircaloy-4 in a 1 N H₂SO₄ solution. It was found that a significant improvement in the aqueous corrosion behavior of zircaloy-4 implanted with cerium ions compared with that of the as-received zircaloy-4. The improvement effect will declined with raising the implantation fluence. The bigger is the fluence, the less is the improvement. Finally, the mechanism of the corrosion behavior of the cerium-implanted zircaloy-4 is discussed.     

Studies on the corrosion behavior of yttrium-implanted zircaloy-4

In order to study the effects of yttrium ion implantation on the aqueous corrosion behavior of zircaloy-4, specimens were implanted with yttrium ions using a MEVVA source at an energy of 40 keV, with a dose range from 1 × 10¹⁶ to 1 × 10¹⁷ ions/cm² at about 150°C. Transmission electron microscopy (TEM) was used to obtain the structural character of the yttrium-implanted zircaloy-4. The valence of the yttrium ions in the surface layer was analyzed by X-ray photoemission spectroscopy (XPS). Three-sweep potentiodynamic polarization measurement was employed to evaluate the aqueous corrosion behavior of zircaloy-4 in a 1 N H₂SO₄ solution. It was found that a significant improvement was achieved in the aqueous corrosion resistance of zircaloy-4 compared with that of the as-received zircaloy-4. The mechanism of the corrosion resistance improvement of the yttrium-implanted zircaloy-4 is probably due to the addition of the yttrium oxide dispersoid into the zirconium matrix.     

城市污水作冷却水时影响316L不锈钢耐蚀性的因素

用电化学方法研究了水质中的Cl-、NH4 -N、化学需氧量(COD)和pH值对316L不锈钢耐蚀性的影响.试验表明:在测试水质条件下,Cl-浓度达到300 mg/L时316L不锈钢点蚀电位有明显的下降;NH4 -N浓度的增加使点蚀电位显著降低;COD的增大使钝化电流有所增大;pH值增大到9时使316L不锈钢钝化电流有明显的增加.     

A multiphysics model for studying transient crevice corrosion of stainless steel

The transient crevice corrosion behavior of 304 stainless steel in NaCl solution has been investigated by a multiphysics coupling model.The model considers local electrochemical reactions,transport of diffe rent species,and homogeneous reactions.The moving mesh method is used to obtain the geometrical change of the crevice wall with time due to corrosion.The level set method is employed to quantitatively describe the influence of the precipitation process on electrochemical reactions.The transient crevice corrosion morphology,potential and current distributions,and pH and chloride ion concentration distributions are obtained by simulation.The effect of crevice geometry factors on the corrosion process is also discussed.The simulation results are in good agreement with the experiments,showing that the model has high reliability.     

Impact of high dose krypton ion irradiation on corrosion behavior of laser beam welded zircaloy-4

In order to study the effect of krypton ion irradiation on the aqueous corrosion behavior of laser beam welded zircaloy-4 (LBWZr4), the butt weld joint of zircaloy-4 was made by means of a carbon dioxide laser, subsequently the LBWZr4 samples were irradiated with Kr ions using an accelerator at an energy of 300 keV, with a dose range from 1 × 10¹⁵ to 3 × 10¹⁶ ions/cm² at about 150 °C. Three-sweep potentiodynamic polarization measurement was employed to evaluate the aqueous corrosion behavior of Kr-irradiated LBWZr4 in a 0.5 M H₂SO₄ solution. Scanning electron microscopy (SEM) was used to examine the surface topography of the Kr-irradiated LBWZr4 after the potentiodynamic polarization measurement. Transmission electron microscopy was employed to examine the change of microstructures in the irradiated surface. The polarization tests showed that compared with the passive current density of the as-received LBWZr4, the Kr-irradiated LBWZr4 is much lower; however, with the irradiation dose increasing from 1 × 10¹⁵ to 3 × 10¹⁶ ions/cm², the passive current density, closely related to the surface corrosion resistance, increased remarkably. The mechanism of the corrosion behavior transformation was due to the recrystallization of the amorphous phase induced by the lower ion irradiation.