کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1252900 1496057 2011 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Monitoring corrosion and corrosion control of low alloy ASTM A213 grade T22 boiler steel in HCl solutions
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Monitoring corrosion and corrosion control of low alloy ASTM A213 grade T22 boiler steel in HCl solutions
چکیده انگلیسی

Rates of corrosion of low alloy ASTM A213 grade T22 boiler steel were monitored in aerated stagnant 0.50 M HCl solutions at different temperatures (283–303 K) using Tafel extrapolation method and the non-destructive electrochemical frequency modulation (EFM) technique, complemented with XPS examinations. Serine (Ser) was introduced as a corrosion-safe inhibitor. Corrosion rates (in μm y−1) obtained from these two methods was in good agreement. Tafel plots showed that Ser acted mainly as a cathodic-type inhibitor. The inhibition process was attributed to the formation of an adsorbed film on the metal surface that protects the metal against corrosive agents. XPS examinations of the electrode surface confirmed the existence of such adsorbed film. The inhibition efficiency increased with increase in Ser concentration, while it decreased with temperature, suggesting physical adsorption. Activation energies have been calculated in the absence and presence of various concentrations of Ser by measuring the temperature dependence of the corrosion rate obtained from the two methods employed. It was found that the activation energy in the presence of Ser is higher than that in bare HCl solution. The adsorptive behaviour of Ser followed Temkin-type isotherm. The standard free energy of adsorption was estimated to be −25 kJ mol−1 at 303 K. These results confirmed the occurrence of physical adsorption.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Arabian Journal of Chemistry - Volume 4, Issue 2, April 2011, Pages 223–229
نویسندگان
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