工业循环冷却水中不锈钢点蚀缓蚀剂的研究

采用极化曲线研究了钼酸钠、硫酸钠及硝酸钠对不锈钢在模拟高硬度高氯循环冷却水中点蚀的缓蚀作用.研究结果表明,三种无机缓蚀剂对不锈钢的点蚀均有不同程度的抑制作用,其效果随溶液温度变化而改变,在低温时,缓蚀作用顺序为硝酸钠＞硫酸钠＞钼酸钠;在高温时,缓蚀作用顺序为钼酸钠＞硫酸钠＞硝酸钠.     

阻垢缓蚀剂对不锈钢管缓蚀效果的评定方法

用点蚀电位法和失重法评价了七种阻垢缓蚀剂在不同冷却水样中对不锈钢的缓蚀效果。用腐蚀失重法评价阻垢缓蚀剂对不锈钢的缓蚀效果，既不合理也很难测准。点蚀电位法是评价阻垢缓蚀剂对不锈钢缓蚀效果的有效方法，但要选择合适的空白水样。     

不锈钢点蚀缓蚀剂的研究进展

详述了不锈钢点蚀缓蚀剂的研究进展,主要介绍了无机缓蚀剂、有机缓蚀剂和复合缓蚀剂等类型的缓蚀剂,并从不锈钢点蚀缓蚀剂的性能、测试方法及其缓蚀作用机理等方面进行了初步阐述,展望了未来不锈钢点蚀缓蚀剂的开发研究方向和前景。     

海洋某油田注水缓蚀剂优选及现场应用探究

针对渤海某油田的注水水质状况,研制了一系列注水缓蚀剂,通过室内验证优选出缓蚀剂HS-4,并通过线性极化电阻法(LPR)对其现场缓蚀效果及点蚀倾向进行了评价.试验结果表明,与在用注水缓蚀剂相比,研制品HS-4缓蚀效果更好,点蚀倾向更低,可满足现场需要.     

不锈钢点蚀缓蚀剂的研究进展

详述了不锈钢点蚀缓蚀剂的研究进展,主要介绍了无机缓蚀剂、有机缓蚀剂和复合缓蚀剂等类型的缓蚀剂,并从不锈钢点蚀缓蚀剂的性能、测试方法及其缓蚀作用机理等方面进行了初步阐述,展望了未来不锈钢点蚀缓蚀剂的开发研究方向和前景。     

2-羟基-4-甲氧基苯甲醛缩氨基硫脲对碳钢的缓蚀作用

合成了一种新型缓蚀剂2-羟基-4-甲氧基苯甲醛缩氨基硫脲(HMBT),采用静态失重和动电位极化曲线法探讨了其在盐酸介质中对Q235碳钢缓蚀性能。结果表明,随着缓蚀剂浓度提高,碳钢的腐蚀速率下降,因此HMBT可以作为一种良好的缓蚀剂。HMBT在碳钢表面的吸附遵循Langmuir吸附等温式,HMBT分子在碳钢表面的吸附自由能表明既包括物理吸附也包括化学吸附。动电位极化的测量结果表明HMBT是一种混合型的缓蚀剂。     

一种复合缓蚀剂对铸铁材料带锈缓蚀保护作用研究

通过浸泡实验检验了单宁酸、环己胺和钼酸钠复合缓蚀剂对带锈铁币的缓蚀效果,采用动电位极化曲线、交流阻抗法研究了铸铁电极在缓蚀剂作用下的电化学行为,并用X射线衍射技术分析了缓蚀作用对试样表面锈层的组成的影响。结果表明,由单宁酸、环己胺和钼酸钠组成的三元复合缓蚀剂对带锈铸铁具有良好的协同缓蚀效果,铸铁电极腐蚀电位正移,且出现了有明显的钝化现象。带锈铁币经缓蚀处理后,表面锈层生成含有Fe_2O_3、α-FeOOH的稳定沉积膜,提高了锈层的耐蚀性能,且锈层颜色变化小,能满足铁质文物保护要求。     

脂肪酰胺类缓蚀剂对碳钢缓蚀作用的电化学研究

开发了一种新型环境友好型N-烷基-N-脂肪酰基氨基脂肪酸盐(TS-417)无磷缓蚀剂。采用极化曲线和电化学阻抗谱方法研究了TS-417对低碳钢在模拟中碱中硬循环冷却水中的缓蚀作用。结果表明:TS-417缓蚀剂对碳钢具有良好的缓蚀作用,属于阳极抑制型缓蚀剂;其缓蚀效率随着缓蚀剂浓度的增大而增大,当添加浓度为100 mg/L时,缓蚀剂效率即可达到90%。     

304SS/NaCl体系中环己胺的缓蚀作用

采用稳态阳极极化曲线、电化学阻抗谱(EIS)、恒电位开路衰减响应曲线和计时电位法等多种电化学测试技术研究了环己胺对AISI 304不锈钢在NaCl溶液中的孔蚀缓蚀性能。结果表明环己胺不仅可以显著降低304不锈钢在NaCl体系中的孔蚀敏感性,而且对蚀孔发展也有较好的抑制效果。缓蚀作用是由于环己胺在金属表面形成吸附层,提高了钝化膜的自修复能力,从而抑制了蚀孔的发生和发展。     

Cr23Mo1N奥氏体不锈钢的耐点蚀性能研究

通过Mott-Schottky曲线、动电位极化、循环极化以及电化学阻抗谱等方法研究了温度对Cr23Mo1N奥氏体不锈钢(HNSS)在3.5%Na Cl溶液中耐点蚀性能的影响。结果表明:随着温度的不断升高,高氮钢的自腐蚀电位和点蚀电位呈下降趋势,腐蚀电流密度逐渐增大,钝化膜阻抗降低,高氮钢钝化膜的半导体性质在不同温度下发生改变,高氮钢随温度的升高点蚀敏感性增大,已发生点蚀的试样不能自修复。并与普通316L不锈钢进行对比,高氮钢表现出更加优越的耐蚀性。     

Electronic structure and pitting behavior of 3003 aluminum alloy passivated under various conditions

Passivity of aluminum (Al) alloy 3003 in air and in aqueous solutions without and with chloride ions was characterized by electrochemical measurements, including cyclic polarization, electrochemical impedance spectroscopy (EIS), localized EIS and potential of zero charge, Mott-Schottky analysis and secondary ion mass spectroscopy (SIMS) technique. Stability, pitting susceptibility and repassivation ability of Al alloy 3003 under various film-forming conditions were determined. Results demonstrated that passive films formed on 3003 Al alloy in air and in Na₂SO₄ solution without and with NaCl addition show an n-type semiconductor in nature. The passive film formed in chloride-free solution is most stable, and that formed in chloride-containing solution is most unstable, with the film formed in air in between. Pitting of Al alloy 3003 passivated both in air and in aqueous solutions is inevitable in the presence of chloride ions. There is the strongest capability for the air-passivated Al alloy 3003 to repassivate, and the weakest repassivating capability for Al alloy 3003 passivated in chloride-containing solution. The resistance of the passivated Al alloy 3003 to pitting corrosion is dependent on the competitive effects of pitting (breakdown of passive film) and repassivation (repair of passive film). According to the differences between corrosion potential and potential of zero charge, passive film formed in air has the strongest capability to adsorb chloride ions, while the film formed in chloride-containing solution the least. Chloride ions causing pitting of passivated Al alloy 3003 in air and in chloride-free solution come from the test solution, while those resulting in pitting of passivated Al alloy 3003 in chloride-containing solution mainly exist in the film during film-forming stage.     

LDH型MoO_4~(2-)缓蚀剂的合成及防腐性能

采用共沉淀法制备了镁铝氢氧化物为层板、MoO24-柱撑的LDH型MoO24-缓蚀剂(记为MoO24-LDH),利用XRD和Raman光谱对样品进行表征。通过缓释实验,讨论了LDH型缓蚀剂的释放能力以及缓蚀剂的缓蚀机理。SEM-EDS、ICP、N2吸附脱附和极化曲线测试结果表明,合成的LDH型MoO24-缓蚀剂具有很好的离子交换和吸附Cl-的性能,释放出MoO24-缓蚀剂进入电解液,24 h内对镁合金的腐蚀电流保持在9.129μA/cm2,减缓了镁合金腐蚀。添加质量分数20%MoO24-LDH颜料的环氧涂层在质量分数3.5%NaCl溶液中的EIS测试体现出较好的耐蚀作用,耐盐雾腐蚀187 h以上。     

再生水用于循环冷却系统时不锈钢腐蚀的研究

采用电化学测试方法研究了再生水用于循环冷却水时对不锈钢腐蚀特性的影响,通过测定弱极化区极化曲线、交流阻抗谱(EIS)和点蚀电位对比分析了TJH-3型缓蚀阻垢剂的缓蚀效果并阐述了其缓蚀原理。研究表明,不加缓蚀阻垢剂不锈钢腐蚀初期钝化膜逐渐发展并于约12 h达到稳定,稳定后平均腐蚀速率极低(约为0.000 15mm/a),但具有较大点蚀倾向。加入TJH-3型缓蚀阻垢剂后钝化膜增长明显增快,膜电阻增大,点蚀倾向显著降低。同时,点蚀电位测试结果表明此复配药剂中各组分对于不锈钢点蚀抑制具有协同作用。     

海洋环境中铝合金标签用缓蚀剂的研究

采用失重试验、极化曲线和电化学阻抗谱等方法,评价了不同缓蚀剂在人工海水中对5A05铝合金的缓蚀效果。结果表明:缓蚀效率依次为钨酸钠>2-巯基苯并咪唑>三聚磷酸钠>钼酸钠>2-巯基苯并噻唑>亚硝酸钠>8-羟基喹啉>硅酸钠>硫酸锌。钨酸钠、2-巯基苯并咪唑和三聚磷酸钠是最佳的缓蚀剂,根据失重试验得出它们的缓蚀效率分别为92.49%、90.47%和89.50%     

Passivation and pitting corrosion of nanostructured Sn-Ni alloy in NaCl solutions

The passivation and pitting corrosion of tin-nickel alloy (34% Ni-66% Sn) in NaCl solution was studied using potentiodynamic, cyclic voltammetry and electrochemical impedance spectroscopy (EIS) techniques complemented by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect of concentration of the chloride ion, the switching potential, scans rate and pH on the electrochemical behavior of Sn-Ni alloy is discussed. The data indicate that the corrosion rate and the pitting corrosion of Sn-Ni alloy increases by the increasing of chloride ion concentration. The observed corrosion resistance of electrodeposited Sn-Ni alloy is due to the formation of a thin passive film from tin and nickel oxides.     

Corrosion Inhibition of Mild Steel in Acidic Medium using 2-amino Thiophenoland 2-Cyanomethyl Benzothiazole

The corrosion inhibition characteristics of 2-amino thiophenol (ATP) and 2-cyanomethyl benzothiazole (CNMBT) on two types of steel in 1m HCl medium were investigated at different temperatures (25, 30, 35, 40 and 50°C). The pitting corrosion behaviour for the same system was studied using a potentiodynamic technique. The pitting corrosion resistance of steel samples increased with increase in concentration of the ATP and CNMBT. Some samples were examined by scanning electron microscopy. The effects of the inhibitors on the general corrosion of the two samples were investigated by using gravimetric and galvanostatic polarization techniques. The inhibition efficiencies increased with increase their concentration but decreased with increase in temperature. Free energies of activation, enthalpies and entropies for the inhibition processes were determined from rate constant data measured and different temperatures at different concentrations of ATP and CNMBT. Results were compared with fits obtained from the application of the Langmuir isotherm. Results were correlated to the chemical structure of the inhibitors. The inhibition efficiency of CNMBT is higher than that of ATP.     

中性体系中MoO_4~(2-)对碳钢垢下局部腐蚀的抑制作用

设计了一种能够模拟垢下局部腐蚀自催化过程的闭塞电池,采用极化曲线和电化学阻抗方法研究了MoO42-对N80钢在近中性NaCl溶液中闭塞区内化学及电化学状态变化的影响。结果表明,MoO24-能有效地减缓闭塞区内pH值降低及Cl-浓集、减弱酸化自催化效应、抑制垢下局部腐蚀。MoO42-的作用机制在于使水合氧化铁腐蚀膜由阴离子选择性变为阳离子选择性,H 可以从膜下扩散出去,而Cl-难以扩散到膜下富集,抑制了腐蚀反应的阴极过程;同时MoO24-迁入闭塞区后增大了电极表面膜层阻抗,抑制了腐蚀反应的阳极过程。     

复配聚天冬氨酸对不同条件模拟水中铜的缓蚀作用

用交流阻抗法和极化曲线法,以模拟水溶液为介质,通过电化学谱图研究了两种环境友好型水处理药剂聚天冬氨酸和钨酸钠的复配对纯铜的缓蚀作用,同时通过改变模拟水介质条件研究复配聚天冬氨酸对铜的缓蚀效果。研究表明,聚天冬氨酸和钨酸钠复配后对模拟水中的铜有明显的缓蚀效果,在缓蚀剂总质量分数为16×10-6,聚天冬氨酸与钨酸钠的质量比为1∶1时,对铜的缓蚀效果最佳,其缓蚀效率为90.50%。当模拟水体系的温度升高、pH增大、氯离子含量增加及硫离子浓度增加时,都会使复配缓蚀剂对铜的缓蚀效果变差。