The Influential Factors on the Triboelectrochemical Behaviors of the Passive Alloys

研究了不同Ｃｒ含量的Ｆｅ＿Ｃｒ合金在Ｈ２ＳＯ４溶液体系中的摩擦腐蚀过程．重点考察了载荷、摩擦速度、Ｃｒ含量及Ｈ２ＳＯ４溶液浓度对摩擦电流密度的影响．结果表明：当摩擦仅作用在金属部分表面时，在钝化电位区，外加载荷和摩擦速度对摩擦电流密度有较大的影响．合金材料耐蚀性的增加或溶液腐蚀性的降低，都将有利于降低Ｆｅ＿Ｃｒ合金材料在Ｈ２ＳＯ４溶液体系中的流失速度The tribocorrosion process of Fe_Cr alloys with different Cr content in H2SO4 solution was investigated.The influence of applied load, friction velocity, Cr content and concentration of H2SO4 in solution on the triboelectrochemical behaviors of the alloys was analyzed. It is shown that applied load and friction velocity have singnificant influence on the tribocurrent density in passive region when friction process occurs on part of the surface of alloy.Increasing the corrosion resistance of alloys or decreasing the aggressive of the solution can reduce the alloy removal velocity.作者联系地址：ＵＮＤＰ／国家科委－北京腐蚀与防护中心,冶金工业部腐蚀、磨蚀与表面技术开放研究实验室,北京科技大学Author's Address: The CorrosionErosion and Surface Technology Laboratory of the Ministry of Metallurgy Industry of China Department of Surface Technology and Corrosion Engineering,Univ.of Science & Technology Beijing,Beiji

Formation and Effect of Tribo Cell for Fe Cr alloy

本文分析、研究了１Ｃｒ１８合金材料在０．２ｍｏｌ·Ｌ－１Ｈ２ＳＯ４溶液中的摩擦腐蚀过程中产生微电偶腐蚀的可能性及原因，并研究了微电偶对摩擦电化学行为的影响．研究结果表明：由于摩擦过程造成材料表面的电化学不均一性是产生微电偶作用的真正原因．未摩擦表面与摩擦表面的面积比显著地影响了摩擦电偶电位和摩擦电偶电流的大小．外加载荷的增大使未摩擦表面与摩擦表面间电化学不均一性加大，从而影响了摩擦电偶电位和摩擦电偶电流的大小．The micro galvanic corrosion of 1Cr18 alloy and its effects on the triboelectrochemical behavior were investigated and analyzed in this article. It is shown that the micro galvanic corroson is due to the electrochemical inhomogenity on the surface of the alloy during the friction process. Like galvanic corrosion,the micro galvanic corrosion behaviors are greatly affected by the area ratio of unrubbed to rubbed surface.The load effects on electrochemical behavior of 1Cr18 alloy are also attributed to existence of electrochemical inhomogenity on the surface of materal.作者联系地址：ＵＮＤＰ／国家科委－北京腐蚀与防护中心冶金部腐蚀—磨蚀与表面技术开放研究实验室北京科技大学Author's Address: UNDP/NSTC Beijing Corrosion & Protection Centre Beijing Univ of Sci & Tech., Beijing, 10008

Oxidation Mechanism of Hypophosphite

对次磷酸盐体系循环伏安曲线－０．４Ｖ（ＳＣＥ）处氧化峰（Ⅱ峰）的特性及本质进行深入研究．结果表明，Ⅱ峰与Ⅰ峰直接相关，对应于活性吸附态的偏亚磷酸根氧化生成磷酸根的电极过程，Ⅱ峰是偏亚磷酸根脱出的Ｈ－ａｄｓ离子在电极上发生氧化的结果．确定了吸附态偏亚磷酸根转变为惰性亚磷酸根反应的控速步骤为偏亚磷酸的脱附过程，并估算了脱附速度常数．最后给出可能的吸附态偏磷酸根氧化生成磷酸根的电极历程及总的次磷酸根氧化机制模型．There exist two oxidation current peaks on the anodic polarization curve between -0.7 V and 0 V(SCE) in Na_hypophosphite solution. Peak Ⅰ (-0.55 V, SCE) , which represents the oxidation process from H 2PO - 2 to H 2PO - 3, has been studied previously. Peak Ⅱ, which is located at the potential about -0.4 V(SCE), is investigated emphatically in this paper. The results show that, peak Ⅰ and Ⅱ are corresponding to two successive steps in oxidation process of H 2PO - 2, i.e. peak Ⅱ corresponds to the oxidation process of adsorped (HPO 2) ads , an intermediate product of electrode reaction of peak Ⅰ, to PO 3- 4. The rate limiting step in the electrode process from (HPO 2) ads to HPO 2- 3 is the desorption of (HPO 2) ads , and the desorption rate constant is estimated as 2.32±0.20 s -1 . A new schematic of oxidation process of hypophosphite is proposed.作者联系地址：ＵＮＤＰ／国家科委—北京腐蚀与防护中心冶金部腐蚀、磨蚀及表面技术开放实验室北京科技大学Author's Address: UNDP Beijing Corrosion and Protection Center, University of Science and Technology Beijing 10008

Electrochemical Evaluation on the Porosity of Electroless Ni-P Alloy Coatings

本文通过研究镍磷合金、镍磷合金镀层和碳钢在不同浓度硝酸溶液中的动电位极化曲线 ,选择了能够快速检测镍磷合金镀层孔隙率的硝酸浓度 ,并对不同厚度的镍磷合金镀层试样进行评价 .结果表明 :镍磷合金镀层在 1 0 %硝酸溶液中的动电位极化曲线能准确地反映镀层的孔隙率 ,该硝酸溶液最适合作为应用电化学方法检测镀层孔隙率的检测溶液 ,其变化规律是随着镀层孔隙率的减少 ,镀层的腐蚀电位逐渐正移 .应用常规的孔隙率检测方法只能检测较大的孔隙 .By investigating the polarization curves of pure Ni P alloy,Ni P alloy coation and carbon steel in nitric acids with different concentrations,the sutable concentration of nitric acid for the evaluation of the porosity of Ni P alloy coatings has been determined and the coatings with different thickness have been evaluated.The results indicated that the nitric acid with 10 wt% concentration is the most suitable solution for the porosity of the coating by using electrochemical method.The polarization curve of Ni P alloy coating in 10% nitric acid can accurately reveal the porosity.With the decrease of the porosity of the coating,the corrosion potential of the coating shifted towards positive direction.Then the ordinary detecion method can only be used in detecting the coating with bigger pores.作者联系地址：北京科技大学表面科学与腐蚀工程系!北京100083,北京科技大学表面科学与腐蚀工程系!北京100083,北京科技大学表面科学与腐蚀工程系!北京100083,北京科技大学表面科学与腐蚀工程系!北京100083Author's Address: Dept. of Surface Science and Corrosion Engi. Coll. of Materials Science and Engi. Beijing Univ. of Science and Tech.,Bejing 100083,Chin

Behaviors of Fe-Cr Alloys during Cavitation Damage

　研究了4种铁铬合金在氯化钠溶液体系中的空泡腐蚀行为.重点考察合金性能及空泡作用区的相对面积对合金空蚀损失量的影响.结果表明:合金空蚀损失量随空泡作用区与非空泡作用区表面面积比的增大而增加;合金的耐蚀性和机械性能同时影响其空蚀损失量.The influence of the surface galvanic effect on the behaviors of three Fe_Cr alloys during cavitation damage in NaCl solutions have been investigated. The results showed that the galvanic effect caused by the inhomogeneity between the undamaged surface of the alloy and the damaged one will be enhanced by the area ratio of the undamaged and the damaged.The behaviors of alloys during cavitation are closely related to both their mechanical performance and anti_corrosion capabilities.作者联系地址：北京科技大学腐蚀与防护中心,北京科技大学腐蚀与防护中心,北京科技大学腐蚀与防护中心,北京科技大学腐蚀与防护中心,北京科技大学腐蚀与防护中心,北京科技大学腐蚀与防护中心 北京100083 ,北京100083 ,北京100083 ,北京100083 ,北京100083 ,北京100083Author's Address: UNDP_Beijing Corrosion and Protection Center, University of Science and Technology Beijing, Beijing 100083, Chin

EIS Characteristics of Anodic Dissolution for P110 Steel under CO_2 Environment

研究了P110油管钢在CO2 饱和的模拟油田采出液中 ,阳极极化下的EIS谱随温度的变化规律 .结果表明 :在低于 90℃的范围内 ,存在一个谱图转变临界温度 ,临界温度之下为三个时间常数型谱图 ,临界温度之上为两个时间常数型谱图 .从阳极反应机理和CO2 腐蚀特征出发对试验结果进行了解释 .Effect of temperature on the electrochemical impedance spectroscopy for P110 steel at anodic polarized potential was investigated in simulated CO 2 saturated oil produced water. The results demonstrated that in the range from room temperature to 90 ℃, there was a critical temperature , below which a three time constant impedance spectrum was observed and above which a two time constant spectrum was shown. A reasonable explanation was given to this phenomenon in an effort to elucidate the mechanism of anodic dissolution and characteristics of CO 2 corrosion.作者联系地址：北京科技大学材料科学与工程学院腐蚀与防护中心!北京100083,北京科技大学材料科学与工程学院腐蚀与防护中心!北京100083,北京科技大学材料科学与工程学院腐蚀与防护中心!北京100083,北京科技大学材料科学与工程学院腐蚀与防护中心!北京100083,北京科技大学材料科学与工程学院Author's Address: Corrosion and Protection Center, School of Material Science and Engineering, University of Science and Technology Beijing 10083 LU Min?xu, YAN Mi lin, ZHAO Guo x

Synthesis of C-20 fullerene during Ar+ ion irradiation

Synthesized C-20 at the target surface of ultra high molecular weight polyethylene during Ar+ ion irradiation at room temperature was studied by high resolution transmission electron microscopy/electron diffraction, rime of flight mass spectroscopy, IR and Raman Spectroscopy. We believe that radiation-induced crystallites consist of caged C-20