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تقيم كفاءة مزيج مثبط التاكل لمحاكاة مياه التبريد باستخدام القطب الاسطواني الدوار == Evaluation of Corrosion Inhibitors Blend Efficiency For Simulated Cooling Waters Using Rotating Cylinder Electrode
Author name:
عبير عبد الخالق القصب
Supervisor name:
قاسم جبار سليمان
General topic:
Chemical Engineering
Specific topic:
Chemical Engineering
Degree:
Master
University:
Al-Nahrain University - College Of Engineering - Department Of Chemical Engineering
Language:
English
University location:
Baghdad
First pages:
38T303 - p.pdf
Abstract:
تم بحث كفائة مثبط التاكل لمزيج من نتريت الصوديوم / سداسي فوسفات الصوديوم على تاكل الفولاذ الكربوني في محاكاة انظمة مياه التبريد من خلال فقدان الوزن وتقنية الاستقطاب الكهروكيميائية. شملت الدراسة تاثير درجة الحرارة30، 45، 60 ?م، سرعة الدوران 200، 600، 1000 | The corrosion inhibition action of a blend of sodium nitrite/sodium hexametaphosphate (SN+SHMP) on corrosion of carbon steel in simulated cooling water systems (CWS) has been investigated by weight loss and electrochemical polarization technique. The effects of temperature 30, 45, and 60 oC, rotational velocity 200, 600, and 1000 rpm, and salts concentrations (0.005 N, 0.01 N, 0.03 N, 0.05 N) NaCl + 0.0736 N Na2SO4 on corrosion of carbon steel were studied in the absence and presence of mixed inhibiting blend (SN+SHMP). Also, the effects of inhibitors blend concentrations of 600 ppm, and 800 ppm (SN+SHMP), at temperatures of 30, and 60 oC, and rotational velocity of 200 and 1000 rpm, on corrosion rate of carbon steel were studied using Second - order Rotatable Design (Box - Wilson Design) to identify the significant effects and interaction in performing weight loss studies and corrosion potential approach. Electrochemical polarization measurements were used to study the behavior of carbon steel in different salt concentrations of (CWS) with pH of 7.5 in absence and presence of the inhibiting blend. The results showed that increasing the temperature, rotational velocity, and NaCl salts concentration leads to an increase in the corrosion rate for both uninhibited and inhibited solutions. The regression model (Box - Wilson Design) that has been developed using experimental data was used to verify that the interaction term of temperature with inhibitors blend and the square term of inhibitors blend are significant for corrosion rate in 0.05 N NaCl solution while the main variables are not pronounced. Also, it is found that the corrosion rate decreases with increases in inhibitor blend concentration up to 800 ppm in 0.05 N NaCl solution. Inhibitor blend concentration of 600 ppm is highly effective giving a high efficiency in 0.005, 0.01 and 0.03 N NaCl solutions of 98.5%, 97.7%, and 96% respectively. Electrochemical polarization studies show that increasing the inhibitors blend concentration (SN+SHMP) shifts the corrosion potential to more noble value (more positive), indicating the anodic nature of the inhibiting blend used.
