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应变和氯离子浓度对304不锈钢点蚀敏感性的影响 总被引:2,自引:0,他引:2
The effects of strain and chloride concentration on pitting susceptibility for type 304 stainless steel were studied in situ using the electrochemical technology under constant strain. The impact factor fc was brought forward to value the effect of strain on pitting. The pitting behaviors of type 304 stainless steel in various chloride concentrations under the strain levels 0%, 10%, and 30% were investigated. Potentiostatic polarization technology was used to study how the chloride concentration affected corrosion current density. The results indicated that fc increased substantially and pitting potential varied remarkably when chloride concentration was over 90 mg.L . Under the three levels of strain mentioned above, when chloride concentration was below 463 mg.L^-1,121 mg.L^-1, and 98 mg.L^-1 respectively, the pitting potential shifted towards positivity and, the passive film became more stable. When the strain was below 10%, the pitting susceptibility of type 304 stainless steel varied greatly as strain increased, whereas the susceptibility only changed a little when the strain was over 10%. 相似文献
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采用声发射技术和电化学噪声技术研究了304控氮不锈钢C型环试样在0.5mol·L-1NaCl与1.5mol.L-1H2SO4的混合溶液中,恒载荷情况下的腐蚀过程。分析了腐蚀过程中所产生的声发射信号的振铃数随时间分布情况,以及不同阶段的声发射信号的频谱特征。同时对比分析了声发射检测结果与电化学噪声检测结果。结果表明,声发射检测技术对于304控氮不锈钢在酸性NaCl溶液中所产生的腐蚀声发射信号很敏感,在不同腐蚀阶段中,声发射信号特征差异明显,对于判断不同腐蚀阶段具有指导意义;声发射与电化学噪声测试结果基本一致,将声发射检测与电化学噪声检测结合使用,有助于使现场检测结果更加可靠。 相似文献
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Results presented in this paper are first that demonstrate instantaneous impedance changes versus reactivation potential detected by means of dynamic electrochemical impedance spectroscopy (DEIS) technique for AISI 304 stainless steel dissolution process proceeding during intergranular corrosion (IG) in 0.5 M SO42− + 0.01 M KSCN solution of different pHs. Application of DEIS method made it possible to evaluate dynamic changes of the examined system's impedance in conditions of IG. As a result, controlling stage of the overall rate of AISI 304 SS dissolution process was determined. Moreover, the paper proposes an alternative way of assessment of AISI 304 SS dissolution rate during intergranular corrosion based on approximation to theory of iron dissolution in sulfuric acid medium. Simultaneously, on the basis of the DEIS measurements it was possible to obtain information about the degree of sensitization (DOS) of the examined material. Accordingly, performed researches revealed the advantage of the DEIS technique over the electrochemical potentiokinetic reactivation (EPR) tests when investigating intergranular corrosion process. 相似文献
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氯离子与冷却水系统中不锈钢的腐蚀 总被引:6,自引:1,他引:5
综述了有关氯离子对冷却水系统中不锈钢腐蚀研究的最新进展,涉及冷却水中氯离子引发不锈钢孔蚀、缝隙腐蚀和应力腐蚀开裂的机理,氯离子的限度,以及影响水中不锈钢腐蚀的其他因素.对如何应对冷却水中氯离子的负面效应提出了见解. 相似文献
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本文讨论了常见不锈钢发生应力腐蚀的介质环境及应力腐蚀机理,然后探究了Cl-浓度、拉应力、溶液温度、溶解氧、pH等因素对腐蚀的影响,并介绍了几种常用的应力腐蚀试验方法和防治措施,对计算机模拟软件在电厂的应用提出了展望。 相似文献
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Weight-loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements were used to study the inhibition of 304 stainless steel corrosion in 1 M H2SO4 at 50 °C by propargyltriphenylphosphonium bromide (PgTPhPBr). The inhibiting effects of propyltriphenylphosphonium bromide (PrTPhPBr) and propargyl alcohol (PA) were also studied for the sake of comparison. For the investigated compounds, Tafel extrapolation in the cathodic region gave a corrosion inhibition efficiency of 98% at 1 × 10–3 M. Adsorption of both PgTPhPBr and PA was found to follow Frumkin's isotherm while adsorption of PrTPhPBr obeys that of Temkin. In the anodic domain, PgTPhPBr acted as a good passivator. The impedance spectra recorded at the corrosion potential (E
cor) revealed that the charge transfer process in the inhibited and uninhibited states controls corrosion of 304 stainless steel. 相似文献