Inhibition Effect of 2-Amino, 5-Ethyl-1, 3, 4 Thiadiazole on the Corrosion of Austenitic Stainless Steel Type 304 in Dilute Sulphuric Acid

• Autor(a) principal: Loto,R. T.
• Data de Publicação: 2014
• Outros Autores: Loto,C. A., Popoola,A. P. I., Fedotova,T. I.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://scielo.pt/scielo.php?script=sci_arttext&pid=S0872-19042014000500004
• topic: corrosion; inhibitor; sulphuric acid; adsorption; Langmuir; steel

The inhibition effect of 2-amino, 5-ethyl-1, 3, 4 thiadiazole (TTD) compound on the corrosion of type 304 stainless steel in 3 M H2SO4 test solution was investigated using potentiodynamic polarization, weight loss techniques and open circuit potential measurements. Results showed TTD to be very effective with an average inhibition efficiency of 98% from weight loss analysis and 87% from polarization test. Data from open circuit potential measurement are well within passivation potentials at specific concentrations of TTD. Scanning electron microscopy showed the effect of the inhibiting compound on the surface topography of the steel, while X-ray diffractometry determined the phase compounds formed on the surface due to inhibitor adhesion. Adsorption of the compound was determined to obey the Langmuir isotherm model. Thermodynamic calculations showed the inhibition process occurred through chemisorption mechanism and results from statistical analysis revealed the overwhelming influence of inhibitor concentration over exposure time on the inhibition performance of the compound.