Atmosfer kirleticilerinin yapı malzemelerine korozif etkisi

TEZ1538Tez (Doktora) -- Çukurova Üniversitesi, Adana, 1994.Kaynakça (s. 120-126) var.vi, 132 s. : rnk. res. ; 30 cm.…Bu çalışma Ç.Ü. Bilimsel Araştırma Projeleri Birimi Tarafından Desteklenmiştir. Proje No: FBE. 90.

Şehir ve endüstri atmosferinde bulunan bazı kirleticilerin demirli malzemeler üzerindeki korozyon etkisi

TEZ688Tez (Yüksek Lisans) -- Çukurova Üniversitesi, Adana, 1989.Kaynakça (s. 71-74) var.vi, 76 s. ; 30 cm.

Impedance measurements of polyester-coated galvanised mild steel in 10xacid rainwater after an accelerated wet-dry test

The variation of defective polyester-coated performance with time in lOxacid rain solution was investigated using electrochemical impedance spectroscopy. Measurements were carried out on samples after an accelerated atmospheric corrosion test. The impedance diagrams (Nyquist plots) were simulated using the EQUIVCRT program which was elaborated by Boukamp and the semi-ellipse model which was developed by Erbil. It has been shown that the defective coating resistance changes with time for the samples subjected to acid rainwater. The corrosion rate of coated metal also changes with time.The variation of defective polyester-coated performance with time in lOxacid rain solution was investigated using electrochemical impedance spectroscopy. Measurements were carried out on samples after an accelerated atmospheric corrosion test. The impedance diagrams (Nyquist plots) were simulated using the EQUIVCRT program which was elaborated by Boukamp and the semi-ellipse model which was developed by Erbil. It has been shown that the defective coating resistance changes with time for the samples subjected to acid rainwater. The corrosion rate of coated metal also changes with time

The Inhibition Effect Of 4,4′-Diaminobiphenyl Against The Corrosion Of Mild Steel İn Hcl And The Quantum Calculations

Bu çalışmada 4,4'-Diaminobifenil’in (4-DB) inhibitör olarak kullanımı araştırılmıştır. Elektrokimyasal teknikler (EIS ve polarizasyon ölçümleri) ve kuantum kimyasal hesaplamalar ((DFT) ile B3LYP/6-311++G (d, p)) uygulanmıştır. Elde edilen sonuçlara göre; 4-DB’nin inhibisyon etkinliği artan konsantrasyon ile artış göstermiştir. Polarizasyon ölçümleri 4-DB’nin anodik reaksiyonların hızını azalttığını göstermektedir. 4-DB’nin inhibisyon etkinliği yüksek HOMO enerjisi (–0,189 eV), dipol momenti (0, 6121 D) ve düşük LUMO enerjisi (-0,019 eV) ile ilişkilendirilmiştir. Adsorpsiyonun Langmuir adsorpsiyon izotermine uyduğu saptanmıştır. Adsorpsiyon standart serbest entalpi (ΔG°ads) değeri hesaplanmıştır.In this study, 4,4′-Diamınobıphenyl (4-DB) is investigated usage of inhibitor molecule. Electrochemical techniques (EIS and polarization measurements) and quantum chemical calculations ((DFT) with the B3LYP/6- 311++G (d, p)) were obtained. The results showed that; inhibition efficiencies increase with increasing concentration of 4-DB. It is found that 4-DB retards anodic reactions according to polarization measurements. The inhibition efficiency of 4-DB is attributed to the high value of EHOMO (–0,189 eV), dipole moment μ (0,6121 D) and low value of ELUMO (-0.019 eV). This inhibitor functions through adsorption following Langmuir isotherm. The value of adsorption free energy of (∆G°ads) was also calculated

POLİÜRETAN KAPLAMALI GALVANİZE ÇELİĞİN KESİLMİŞ KENAR KOROZYONU: FARKLI SÜRE VE BAĞIL NEMLERDE SO2 GAZININ ETKİSİ

Bu çalışmada kesilmiş kenar poliüretan kaplamalı galvanize çelik örneklerin atmosferik korozyonuna farklı bağıl nemliliklerde SO2 gazının etkisi araştırılmıştır. Bu amaçla örnekler bağıl nemlilikleri %70 , %80 , %90 ve %100 e ayarlanmış test hücrelerinde 20, 40 ve 60 gün süreyle SO2 gazı etkisinde bırakılmıştır. Çalışma da test hücresinden çıkarılan örneklerin, impedans ölçümleri yapılmış, Nyquist diyagramları, Lineer Polarizasyon Direnci ve Anodik akım potansiyel eğrileri elde edilmiştir. Elde edilen sonuçlara göre kesilmiş kenar poliüretan kaplamalar genel olarak %70 bağıl nemde koruyuculuğunu çok az kaybetmiştir ancak %80, %90 ve %100 bağıl nemliliklerde organik kaplamanın koruyuculuğun bağıl neme bağlı olarak büyük oranda kaybolduğu görülmüştü

Investigation of the cut-edge corrosion of organically-coated galvanized steel after accelerated atmospheric corrosion test

The cut edge corrosion of organically coated (epoxy, polyurethane and polyester) galvanized steel was investigated using electrochemical impedance spectroscopy (EIS). Measurements were performed on specimens that had been tested in an accelerated atmospheric corrosion test. The samples were subjected to 10 s fogging and 1 h awaiting cycles in an exposure cabinet (120 and 180 days) with artificial acid rain solution. According to the investigation, the coatings were damaged from the cut edge into the sheet, this distance was about 0.8 cm. These defects were more pronounced at after 180 days in proportion to after 120 days

1-(2-Hydroxyethyl)-2-imidazolidinone as corrosion inhibitor of mild steel in 0.5 M HCl solution: thermodynamic, electrochemical and theoretical studies

The inhibition effect of 1-(2-Hydroxyethyl)-2-imidazolidinone (2-HEI) on mild steel (MS) corrosion in 0.5M HCl solution was investigated at different inhibitor concentration and temperature by electrochemical experiments, such as linear polarization resistance (LPR), electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and quantum chemical calculations. The inhibitor adsorption process on mild steel in 0.5M HCl system was studied at different temperatures (20 C–50 C). Furthermore, the surface morphology of MS was also investigated with SEM in the absence and the presence of inhibitor. The adsorption of 1-(2-Hydroxyethyl)-2-imidazolidinone on MS surface is an exothermic process and this process obeys the Langmuir adsorption isotherm. The Quantum chemical findings are good agreed with the empirical data

Sodyum Dietil Ditiyokarbamat Trihidratin İnhibitör Olarak Asidik Ortamda Yumuşak Çelik Korozyonuna Elektrokimyasal Davranışının İncelenmesi

Inhibition performance of sodium diethyidithiocarbaminat trihydrat (SDDT) against corrosion on mild steel (MS) in 0.5M HCl solution investigated by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and linear polarization resistance (LPR) methods. The inhibition efficiency increased with increasing of inhibitor concentration. The potentiodynamic polarization results indicated that all the studied inhibitors act as mixed type. SDDT adsorption on the MS surface obeyed the isotherm of Langmuir and the thermodynamic parameters; Kads, ΔG○ads were also calculated and discussed