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运用恒电量技术对冷却水系统的腐蚀进行监测,通过Rp、Fr、Cf等电化学参数的分析,能够随时报道水处理各阶段的腐蚀变化,尤其是能够灵敏地反映出预膜膜层生长情况。 相似文献
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介绍了以8098微控制器为核心的智能腐蚀测试仪的功能,工作原理,硬件、软件设计和行之有效的信号处理技术。 相似文献
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钢筋钝化膜在含缓蚀剂的模拟混凝土孔隙液中的电化学特性 总被引:1,自引:0,他引:1
应用线性极化法、Mott-Schottky曲线研究了钢筋钝化膜在含有亚硝酸钠和D-葡萄糖酸钠复合缓蚀剂的模拟混凝土孔隙液中的电化学特性.结果表明,复合缓蚀剂的加入,使钢筋在含有氯离子的模拟混凝土孔隙液中耐蚀性提高;在外加亚硝酸钠的模拟混凝土孔隙液中,钢筋钝化膜在一定的电位区间内呈现n型半导体特性并具有单一施主浓度,而D-葡萄糖酸钠加入则增大了施主浓度.此外,钢筋钝化膜的耐蚀性和半导体性质受溶液中氯离子浓度的影响较大,加入一定浓度的氯离子可使钝化膜的施主浓度增大,耐蚀性降低. 相似文献
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采用电化学噪声技术(EN)和电化学阻抗谱(EIS)研究了Q235钢在0.5 mol/L NaCl的饱和Ca(OH)2溶液(SCP)中的腐蚀过程,并对噪声数据进行时域分析与频域分析,对阻抗谱数据进行等效电路分析。采用SEM结合EDS和XRD研究了Q235钢的表面形貌和结构组成。结果表明,Q235钢在SCP溶液中的腐蚀过程可分为钝化膜的形成与破裂阶段(Ⅰ)、亚稳态点蚀阶段(Ⅱ)和Ca2+沉积和腐蚀产物形成阶段(Ⅲ)。在(Ⅰ)阶段,电流噪声的波动幅值较小,电流噪声标准偏差SI、白噪声水平WI较小、噪声电阻Rn较大;在(Ⅱ)阶段,电流噪声波动幅值较大,SI、WI呈现阶跃式增长,Rn显著降低;在(Ⅲ)阶段,电流噪声波动幅值增大到200 nA,SI、WI、Rn平稳波动。Q235钢在SCP溶液中腐蚀10 d后在其表面出现Fe2O3和弥散分布的CaCO3晶体,此时阻抗谱中出现类Warburg阻抗,腐蚀反应受电荷转移和O2扩散的联合控制。 相似文献
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Corrosion Evolution of Reinforcing Steel in Concrete under Dry/Wet Cyclic Conditions Contaminated with Chloride 总被引:1,自引:0,他引:1
The corrosion evolution of rebar in concrete was monitored by electrochemical impedance spectroscopy(EIS) under dry/wet alternated accelerated corrosion test.Four stages with different dynamic characteristics were observed during the corrosion evolution.They were passive stage,local corrosion controlled by the charge transfer step,accelerated corrosion controlled by the mass transfer step,and constant rate corrosion controlled by the mass transfer step through a barrier layer.X-ray diffraction(XRD) analysis showed that the corrosion product of rebar in mortar was composed of α-FeOOH,γ-FeOOH and Fe 3 O 4.The corrosion mechanisms of all four stages were discussed and the corrosion reactions were proposed according to the corrosion product and corrosion evolution characteristics. 相似文献
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动海水腐蚀模拟试验的发展 总被引:2,自引:0,他引:2
综述了动海水腐蚀模拟试验的研究概况,主要阐述了旋转试验、管流式模拟试验、喷射冲击试验、高速冲刷试验等4类试验方法及其优缺点,进而展望了动水腐蚀的研究动向和发展趋势。 相似文献
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Baigang AN Xueyuan ZHANG Enhou HAN Honxi LIState Key Lab. for Corrosion Protection of Metal Institute of Metal Research Chinese Academy of Sciences Shenyang China.School of Chemical Engineering Anshar University of Science Technology Anshar China. 《材料科学技术学报》2004,20(2):220-222
Under the condition of simulated rain precipitation in the laboratory, with EIS and SEM observation, the effects of pH value of simulated rain on corrosion and runoff behavior of carbon steel A3 were studied. The corrosion rate of A3 steel increased and runoff action of rain precipitation on A3 steel surface was intensified with decreasing pH value, of simulated rainwater. The runoff and corrosion traces were formed along the flowing direction of rainwater, which appeared more apparently with decreasing pH value. 相似文献
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为深入揭示亚硝酸盐阻锈剂提高钢筋混凝土结构耐久性的机理,采用动电位极化技术、X射线光电子能谱(XPS)和原子力显微镜(AFM)研究了亚硝酸钙阻锈剂对钢筋表面生成的钝化膜的影响。动电位极化研究结果表明:未添加阻锈剂时,钢筋发生点蚀的临界氯离子浓度在0.05~0.06 mol/L之间,添加亚硝酸钙阻锈剂后,钢筋发生点蚀的临界浓度增大至0.18~0.20 mol/L,表明亚硝酸钙阻锈剂提高了钢筋表面钝化膜的抗点蚀能力。X射线光电子能谱的研究结果表明:钢筋表面生成的钝化膜的成分均是由铁的氧化物(Fe_(ox))和铁的氢氧化物(Fe_(hydrox))组成,亚硝酸钙阻锈剂降低了钝化膜中Fe_(hydrox)的含量。原子力显微镜的研究结果表明:亚硝酸钙阻锈剂的添加使得钝化膜的表面更加光滑平整。 相似文献
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Yimei Wang Yan Liu Lin Liu 《材料科学技术学报》2014,30(6):622-626
Fatigue behaviors of a biocompatible Ni-free Zr60.14Cu22.31Fe4.85Al9.7Ag3 Zr-based bulk metallic glass (BMG) have been studied under three-point-bending test in a simulated body fluid (SBF) at 37 ℃ and compared with those in air at room temperature (RT). The BMG shows a high fatigue limit of approximately 366 MPa in SBF, which was slightly lower than that in air (400 MPa). The fatigue cracks tended to initiate from the defects such as cast-pores, inclusions and corners of the samples and propagate in a similar path in SBF and in air. Three distinct regions, i.e. a crack-initiation region, a stable crack-growth region and an unstable fast-fracture region were clearly observed on the fatigue-fractured surface. Although pitting occurred at the defects where crack initiated, it does not affect significantly the fatigue life of the BMG, because the lifetime in the present BMG is mainly determined by crack propagation. The high corrosion-fatigue limit of the studied BMG results from its excellent corrosion resistance in SBF and intrinsically good toughness. 相似文献
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